Competitive Swimwear Sizing Guide

Competitive Swimwear Sizing GuideSelecting the correct swimsuit size can be challenging, especially for athletes new to competitive swimming and fitness swimming. Sizing swimwear using only waist and chest measurements will get you headed in the right direction, but this is only the beginning.

Read on for Kiefer’s advice on how to get a great fit from your swimwear.

Swimwear Sizing Challenges

Generally speaking, swimsuit sizing charts provide excellent guidance. Nonetheless, two challenges remain, regardless of size chart accuracy:

  1. Swimmers may be unfamiliar with how to take measurements.
  2. Athletes may be unfamiliar with what a good fit  feels like.

How To Take Proper Swimsuit Measurements

Taking fresh measurements and matching them to a swimsuit size chart is the best approach for a great fit.

Here are some guidelines for making proper swimwear measurements:

  • Don’t take your own measurement – ask a friend to measure you.
  • Take measurements on bare skin!
    • Bonus Tip: If this isn’t possible, adjust measurements to remove measuring overstatements caused by bulk from clothing.
  • Use a soft tape to measure. No rulers – no metal tape measures – soft tape only!
    • Bonus Tip: The tape should lay flat, without indenting skin. Over-tightening distorts measurements.
    • Extra Bonus Tip: If a soft tape measure isn’t an option, use non-stretching string – and carefully match the string length to a reliable measurement tool.
  • Warning For Guys: Gentleman, your measurements are less challenging – but be careful! Remember:
    • Measure 1″ below your navel to determine your waist size. Waist measurement equate to the suit size, so a 32″ waist should order a size 32 suit.
    • Do not use the pants size shortcut! Pants size is not an accurate equivalent, because it is often chosen by the look or style of the fit, instead of an actual measurement. Save yourself some frustration and measure your waist.

Chest & Hips – Special Swimsuit Sizing Situations

All bodies are different, and women with greater variations between chest and hip size may want to consider downsizing or upsizing as follows:

  • Small Chest / Large Hips: Consider upsizing above chest measurement guidelines.
  • Big Chest / Small Hips: Consider downsizing below chest measurement guidelines.

What Not To Do:

  • Don’t reference a size from an old swimsuit!
    • Old suits can be stretched out and will not index your current sizing needs.
    • Department store swimsuits and fashion swimwear brands are not designed or cut to fit like fitness swimwear.
    • Sizes can vary across brands & suit cuts can change over time.
  • Don’t let someone else order for you! The fit of your swimwear is a personal preference – don’t let someone’s speculation about sizing get in the way of basic swimwear sizing strategies.
  • Warning For Guys – Don’t Use Your Pants Waist Size! Because pants size is often chosen to achieve a certain fit style, translating it your swimwear waist size isn’t recommended.

What Does A Great Swimsuit Fit Feel Like?

For best results and to maximize the life of your swimwear, Kiefer recommends that swimsuits provide a tight & supportive fit.

For swimmers that are skeptical about the benefits of tight-fitting swimwear, we offer the following encouragement:

  • The suit you are trying on is as tight as it’s ever going to be and will loosen over time.
  • The feel of the suit will change once you are in the water.
  • Bag = Drag! Any bag or wrinkles will cause unwanted drag during your race or workout.
  • Swimsuits are more than a means to cover your skin. Like running shoes, competitive swimwear is a piece of sports equipment. And like shoes that are too large, wearing an over-sized swimsuit will cause discomfort and hinder athletic performance.

Fit Differences Between Nylon vs. Polyester Swimwear Fabric

  • Polyester material has a tighter, more compressive fit and wears longer. This does not mean you should upsize for poly, but swimmers should consider sizing up if on the cusp on a larger size.
  • Nylon suits:
    • Have more stretch, but should still have a snug and supportive fit.
    • May need to be replaced semi-annually.


It’s important to remember that jammer cuts have changed over the last few years. Although Jammers used to fit lower on the waist, more current cuts have a higher waist. Here are some extra jammer fitting tips to help you determine what a great fit feels and looks like:

  • Jammers should be sufficiently snug at both waist and knee, to make getting 2 fingers under the fabric somewhat challenging.
  • Waist fit rules! Don’t worry about the leg cuff height, as this will vary for different body types.
  • Remember, your waist measurement equates to the suit size, so a 32″ waist should order a size 32 suit.

How Can I Tell If My Swimsuit Is Too Big Or Small?

Big – a swimsuit is too big if:

  • Suit material is wrinkled or bagging.
  • For women, swimwear is too big if:
    • Scooping at neck occurs when holding a “streamline” position.
    • Suit straps can be raised to ear height.
    • The open part of the suit back (below the intersection of the straps) lifts off the skin.

Small – a swimsuit is too small if:

  • It restricts or limits athletic range of motion.
  • Ouch – it hurts!
  • It limits your circulatory system – blood flow and/or breathing!
  • Putting it on is a struggle.
  • It causes excessive muffin topping anywhere on the body.
  • Your chest is spilling out of suit.

Whoa! Did you get all that?

I hope this helps you when considering sizing for your next swimsuit. Please share your comments – or any advice you have for swimwear fitting.

Do you have questions?

We’d be happy to help, just let us know!

See you at the pool.

Learn More About Swimwear:

About Kiefer Swim Products

Performance Gear For Swimmers. Today Kiefer is a multifaceted company but still purely focused on serving the aquatic industry. We have expertise in engineering world class products like our custom starting blocks and racing lanes for all levels of aquatic facilities. We serve the lifeguard and aquatic safety and rescue industry with a full line of products that absolutely perform when you most need them to, and we serve the competitive swim business with the products needed to swim at the highest level.

74 Comments on “Competitive Swimwear Sizing Guide”

  1. Hi, so im looking for a new racing suit bc my last one broke. It was a speedo lzr x closed back and i got it in the size 23. But the problem is that my measurements are all over the place. My body-loop matches size 25, chest is 24, and waist is 23… should i rather buy the 24 or 25?
    thanks for any help

    • Aplogies for the slow reply, I would suggest trying to find a vendor who can either allow you to try them on or fit you to a size in shop. Tech suits are big investment nd making sure you have the right one is imperative!

  2. Hello, I just started competing swimming. My coach recommended I get a 26 now that I’ve worn it feels to snap and makes me have a muffin top while my first one a 36 never did. What should I do to stretch it since custom orders cannot be returned or exchanged.

    • Hi Melanie! Is this a racing/tech suit? If yes, they should feel tight, but if you are uncomfortable wearing it I can completely understand. The more you wear it the more it will stretch out. 36 to 26 is a pretty big jump, I always recommend going in to a specialty store if you have the opportunity to try things on. If that isn’t an option and you are attending swim meets vendors can often assist with fitting. Hope that helps a bit!

  3. Do you typically drop down one size (based on waist) for a boys tech suit to make it more compressive than a practice suit or donmosy of the major brands take that into account when making and sizing tech suits? Thanks for all the good info but I didn’t see this addressed previously.

    • Hello Gary! Honestly it really depends on the swimmer and their body. In general I would say it is not unusual for any swimmer to size down with tech suits, but my recommendation is to always try and get to a shop or meet where you can try on whatever you are thinking of purchasing to be 100% sure.

  4. We were at a winter gala in South Africa and Speedo South Africa had a stand there. They were selling racer swimsuits at half price for only one day. My daughter is 13 and relatively small built. We weren’t allowed to try on any suits, and were told we also couldn’t return any suits, once we’ve bought & tried them on. The lady sized my daughter a 20 GBR. We bought the Speedo LZR Racer X size 22 (I didn’t believe that a size 20 or even 21 would fit). That evening it took me & my husband 40 mins (with lots of baby powder) to help my daughter get the suit on. It was a painful process. The next morning when we tried putting it on for the gala, it tore at the the back. We were devastated! It was not a cheap suit for us. Later at home we measured her again and she is between a 22 and 23. Should I go back to Speedo South Africa and complain? The gala ran over two days and naturally Speedo did not return the next day. At least 2 other people there bought too small sizes based on advice from Speedo. The swimsuit cost me R2500. I bought it for her because she was selected for a regional junior development squad. Now I am stuck. Even if I have it sown eith a patch, I am not comfortable it won’t tear again. Any guidance/advice appreciated. Thank you, Jelane Barnard

    • I’m so sorry Jelane. I do always feel like it helps to reach out to the company. The worst they can say is no! However if you do nothing, nothing happens. Sometimes just a honest but polite call/letter can work wonders. Best of luck.

  5. How do I know when to switch my 13 year old from a boys to a men’s jammer. He can wear a men’s small shirt. Actually those fit better and are smaller than a boys size 16 shirt. The waist size of the jammer overlaps. I can get him a 26 or 28 in boys or a 26 or a 28 in men’s . How do I decide?

    • Hi Kristin! You know I cannot speak for all brands, but the designation of mens vs boys sizes is really just categorical. For example boys sizes only go up to ‘insert random size here’ because MOST boys won’t be bigger than that size. The smaller sizes tend to be tailored slightly more towards boys than men. Perhaps try a 26 in men’s and see if he feels like it fits any differently? Otherwise head into a sporting goods store or local swim shop or even the on deck vendor at meets to try them on and see what he prefers.

  6. I know that different suits are better for different events. What do you recommend for men’s distance freestyle? Thanks!

    • Hi Jani, I preferred having my legs covered when I swam distance, but I am female and it really does boil down to personal preference. When you look at fields of racers take a look at what you see, perhaps that might give you further insight to what preferences different swimmers have based on stroke and distance.

  7. Hi there. I’m looking for a technical swimsuit for my girlfriend but one thing that does matter is her bust. 30H. She really likes the TYR Avictor kneeskin but what size does she need? Thank you.

    • Linh I wouldn’t be helping to make a guess without seeing her and fitting her myself. I recommend trying to find a shop with a sizing kit or attending an event with vendors that can help you in person.

  8. My chest and waist measurements put me at one size, but my torso puts me in a suit one size larger…which measurement is the most important when choosing the right size race suit? I’ve heard hips over chest, but nothing about torso.

    • I highly recommend getting yourself into an actual racing suit to be 100% certain. There are stores and events where you can try on the tech suits so you aren’t blindly purchasing a several hundred dollar suit. I can’t tell you which route I’d lean towards unless I could see you in our shop, it wouldn’t be accurate any other way.

  9. Hi. I’m having trouble with swimsuit sizing and I like TYR swimsuits. I own a size 30 but too big and a size 24 way to small. I don’t know which one to get a size 26 or 28. I’m 5ft 111 for weight. Bust size 34C please help. Which one should I get

    • Yenifer I make a point to never tell anyone over the internet what size they should get. It wouldn’t be responsible of me. I recommend trying them on. If you know a 30 is too big and a 24 is too small find a store that carries the other two sizes in between and find your perfect fit.

  10. Hi. I like to know exactly how tight a Speedo brief should fit. Is there a rule of thumb regarding the tightness? Thanks.

  11. hi i was looking for a jammer for myself and found the Fastskin Endurance+ High Waisted Jammer

    and i was advised that i should take a size smaller than my waist and i wear 32 inches speedo jammer into practice and thats a little loose so should i take 30 or 28 in fastskin endurance +

    • For a technical suit you do want it to fit tightly, however it wouldn’t be fair of me to tell you what size to purchase without seeing and fitting you myself. I would definitely recommend trying one on if you can find a shop with a sizing kit. I imagine a 30 would do just fine, but a 28 may also give you that added compression that swimmers like.

  12. Hi! I bought a Speedo LZR racer Elite 2 for my daughter in size 25L, that fits her fine. I want to buy the Speedo LZR racer X for her now, what size should I get in that. What would you suggest.

    • I highly recommend you take her in to be fitted. Any advice I give on sizing without actually seeing your daughter would be flawed. Even though they are the same company, its always best to see a tech suit in person and get her sized. Until she stops growing I would always take this route first to avoid the hassle of trying to return or having to rebuy.

  13. Hi there please help got speedo elite 2 high waist for my -11 year old son who is big and measured at size 26…now finally getting them he thinks they are too high on waist…actually up to naval. .. is that too high ?. Thanks for your comment.

    • Richard, the high waist is supposed to sit right up by the navel. If your son is comfortable in the suit then I wouldn’t worry about it, however if he feels like it doesn’t fit right then you might want to try a different cut.

  14. So I do team Swim and i Recently got an swimsuit I’m normally a 40 but the 40 I can put the strapes past my ears,But I got an 36(the size they only had)But the 36hugs. Me a little and I can lift the strapesbut not to high and it’s a little tight in the back what should I do?

    • That’s a personal call Sarah. If you can lift the straps off your shoulders and its just tight that doesn’t mean its a bad fit. Suits should fit snugly. However if you are uncomfortable that is the real deciding factor. If you aren’t comfortable in your 36, try to exchange it for a 38.

  15. Hello I am looking at 34 & 36 size Speedo Jammers & I did the waist measurement as recommended & I’m a 35. I just started swimming in Pre-Masters lessons, so I’m also anticipating to lose a little more weight & waistline. The 34 has no wrinkles but the cuffs at bottom are a little tight. It’s snug but not painful to put on. The 36 fits well but has a few small wrinkles on left & right front below the waist. The 36 is 50%poly PBT/50 poly. The 34 is 78% Econyl recycled nylon/22% Lycra.Can you guide me on a choice? Thank You, Darren

    • Hi Darren, the 36 will stay more true to size because it is a poly blend. The 34 will loosen up much more quickly because it is nylon and lycra. Comparing the different materials in different sizes is a little like apples and oranges. If you anticipate loosing weight, and the 34 isn’t uncomfortable, I’d try that route but in the poly blend, plus it will last much longer.

  16. My little son needs jammers with a slightly shorter leg. Are there any styles from any brand that have just a few less inches?

  17. Hi i ordered speedo mindover brief- power plus size 32 for training, my hip and waist are 38 and 34 and it suits perfectly according to speedo site. But they feel too compressive on thigh, i can see light red line when i wear them litle longer. Do you think i shoul exchange size to 34?

    • Nikola, the suit should be compressive and will leave marks on your skin after wearing it. I wouldn’t call that abnormal. If you are uncomfortable size up. I always purchase training suits in a comfortable size and technical suits in an uncomfortable size. The difference is the suits purpose. You want that compression in a racing scenario but don’t necessarily need it in a training one.

  18. Im considering between a size 30 and 32 for TYR Durafast Elite Crosscutfit One Piece Swimsuit. I fit the measurements (for size 32) for chest and waist but not the hips and torso. I am a 32 chest, 25.5 waist, 31 hips, and 56 torso. Which size should I get?

    • Hi Zoie, if you prefer a tighter fit size down, if comfort is more your speed size up. In the end I’d attempt to try them on in person at a swim shop, but I realize that isn’t always possible. If you have a short torso but are bigger busted the 32 would probably be fine, however if you have a short torso and not so busty the 30 might be more appropriate. The torso length is a more important measurement than the hip.

  19. My daughter just bought a speedo LZR elite 2 in a size 26. She says that was hard to get on but it “fits”, but According to the sizing guide she should be a 24. It also only took her 8 mins to get on while she’s dry. Should she get a 24.(her practice size is a 28-32)

    • Hi Jenna, unless I could see your daughter in the suit it would be hard for me to assess the fit. I recommend she consult her coach on the matter if she feels it isn’t quite right.

  20. Is there any discussion about how small girls suits are today in the competitive swimming world? They are wearing them more like a Brazilian cut in the back. It it really inappropriate and setts the wrong message to younger female swimmers. Just curious if there are any articles you know of on the matter. Concerned parent.

    • Mika I haven’t discovered any active discussions on the topic, but as a parent I understand your concern. As a swimmer sometimes the different cuts are more comfortable for whatever reason to the individual swimmer. As a coach I am bothered by some of the current cut out styles because I have witnessed young females wearing them struggle with them staying in place while training and in general cover the bare spots with their hands when they are out of the water. All I can recommend is buy suits you and your swimmer are comfortable with.

  21. Elizabeth, perhaps a suit with a tie back could help with your sizing woes. There are several competitive suit makers that have them available and it makes them more adjustable than their solid back counterparts.

  22. I have a classic coke-bottle shape, where my torso is considerably more slender than my hips. Is there a brand I should look at that best fits this sizing discrepancy? Two pieces have worked for me because the tops always roll up on me.

  23. I find it hard to find a swimsuit that doesn’t either cut my bum in half or bag around the chest. Is there a lesser evil?

    • Hi Sarah! Yes there is a lesser evil, you just haven’t found it yet, I wish I could tell you with certainty it’s brand A, B, C or D, but I can’t. Just keep trying different things and eventually you will find The One. Best of luck!

    • Some swimmers use shoes for added training intensity, but I don’t think it would prevent or cause warts. Swimming wouldn’t be the cause for that particular kind of skin issue.

  24. With the elasticity of briefs and jammers I imagine that the measurement would be just fine despite hips often being wider than the waist. The measurement advice Robin gave for 1″ below the navel gives a compromise of sorts.

  25. Great article. And although you were very clear about mens’ measurements, “Waist measurement equate to the suit size”, I just want to be clear that even though a brief is worn at the hips, which may be wider, you still go by the man’s waist size?

  26. If your son’s waist is a 26.5 he may be more comfortable in a jammer size 28. Jammers are offered in a size range that jumps by 2’s – 26, 28, 30, etc. Unfortunately, jammers are not offered in long sizes. A Kiefer, Speedo, TYR or Dolfin jammer should all supply adequate coverage.

  27. Our son is getting ready for his second year swimming so we’re still pretty new at this. He hit a growth spurt and changed overall body proportions. He needs new jammers, size 26.5 waist. The problem we had when he tried on a few suits today was that they were all too short in the waist. Rather than the traditional low waist jammers fit that allows the swimmer to bend over without exposing themselves, every suit showed his rear end. He’s not interested in showing ‘plumbers crack’ every time he’s working out or on the starting block! They were very low in the front too. Are there any boys suits sold in “long torso” or “tall” sizes that will give another two inches or so of coverage?
    I just had a thought. Are men’s jammers a bit taller in the waist? Do they come in size 26 – 28?

  28. Hoping you can shed some light: I recently ordered Size 28 jammers for my son who is a competitive swimmer-replacing the pair he has because they are “too short”. He is 13, very tall with long legs (36in inseam) and doesn’t like that this new pair also fits about 2 inches above his knee. I also think they are too tight (getting a finger into the waist is nearly impossible) but he says they are fine. Is there a “proper” length or is it luck of draw on the manufacturer and body type? I’ve tried looking for a length in the descriptions but no luck there either. Any help would be appreciated.

    • That’s a great question. Generally, jammers are very long on smaller boys – and sit right at the knee. However, with a 36″ inseam- your son is never going to fall into the “smaller” category.
      As you know jammer lengths increase with waist size, not in proportion to leg length. Jammers will sit higher above the knee for older kids and adults; especially long, lean swimmers.

      Kiefer jammers measures as follow:
      size 28 – inseam 7.87″ outseam 15″
      size 30 – inseam 8 1/4″ outseam 15 3/4″

      In any case, your son will know if the fit is overly tight. Tight-fitting suits are preferred, unless they’re limited athletic movement.

      In the meantime, a jammer that falls higher on your son’s leg just might be the reality of his body type – but I don’t think it will hold back his performance.

      If we hear about longer cut jammers, we will definitely let you know!

      best of luck!

  29. I have heard from a couple of people that if your finger can fit through any opening of the suit it may be too big since water can get in there. is this true?

    • Any bagging will reduce performance, so the 1 finger test could be a could determinant for the fit of a racing suit. if fitness swimming (and comfort) is the primary application for your swimwear, a less stringent approach is ok; but no bagging, for sure. ultimately, you want to practice full range of motion across all the mechanics of turns and swim strokes to assess the fit, to make sure water isn’t being acquired and trapped. you’ll be able to feel when you’re dragging along extra water- and it will annoy most swimmers!

  30. For my school swim team I ordered a suit that is one size too small. I cant replace it or get a new one so I’m stuck with it..Its a polyester and its really tight because its supposed to be for swim meets only. What should I do? I was thinking I would just wear it in the water and wait for it to loosen up?If so, how long will it take for it to get a little bigger?

    • Poly stakes a while to loosen; it’s designed to hold it’s fit. It will loosen eventually, but it could be a tight squeeze for a while. I’d check around with other swimmers on the team to see if any want to size down. Best of luck!

  31. I just bought a Enduro Super, I haven’t used it yet. But I tried it on and it feels like my shoulders are being pulled down making me want to hunch over. Is that normal?

    • You bought an endurance fabric suit with a superproback? Endurance fabric will be very taught and compressive, but it should not limit your athletic motion. If the suit has the wrong fit it cold limit your performance- and give you a suit burn on your shoulders… please let me know what suit you bought specifically. thanks

  32. I am trying to decide between a size 30 and a size 32 nike powerback tank swimsuit. I am a lap swimmer and want a polyester swimsuit. My shoulders seem to be a little red and my shoulders seem to ache a bit. It is a new suit so I don’t know if it will stretch. The 32 is more comfortable in the shoulders but seems to crinkle a little in the butt. I am a 35.5 bust, 29 waist, 36 hip, and torso is about 60.5

    • Hi, i checked with Stacey Kiefer; she said that Nike suits traditionally run a little large. If you’re on the fence about sizing up or down, she recommends sizing down to the smaller size. Plus, the suit will stretch over time. hope that helps! let us know how it goes…

  33. Thanks for this Robin! I am short but with a very long torso. I’m trying my first poly suits as I am doing more water exercise. I finally found a size the gets on ok but I feel kind of “compressed” in the torso. Is this normal? Can I expect a poly suit to stretch over time? Is there a brand known to have longer torsos? Thanks!

    • Yes, it is very normal to feel compressed in Poly, and in the torso in particular. Polyester swimwear will stretch slightly and gradually over time. I haven’t seen Poly suits in a long torso, but Lycra Speedo Ultrabacks are available in long sizes.

    • Oops, quite right! Generally speaking, men’s waist measurements for men equate to the suit size, so a 32″ waist should order a size 32 suit. Women’s size conversions are much trickier – use the size chart assigned to each swimsuit for the best fit. thanks

  34. Really helps…thank you…i would prefer to try on a suit, but no one around carries elite racing swimwear…St George, Ut…if im going to spend between $300 to $500… I want to try it on…i bought a kneehi made in japan and lucked out….At under $40… And it fit perfectly…

    • I’m glad it worked out – as you noticed, sizing somethings requires a leap of faith – but good measurements shorten the leap!
      We’ll be following up with an article on “tech suit” sizing in the near future.
      Thanks for your comments! See you at the pool…

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