Sport & running
How many seconds does a racing swimsuit take off?
A 1–2% time band when you add or remove the 2008–2009 non-textile suit, and which pool suits are illegal in a World Aquatics race.
Quick answer
A longer suit is not a faster time. The seconds people attach to a racing swimsuit come from one generation, the non-textile polyurethane suits of 2008 and 2009, and only as a band. In 2008 that generation shifted the mean of the world’s top-10 times by about 1.2% in men’s events and about 1.0% in women’s events (Berthelot and colleagues, Materials Today, 2010). This page uses 1–2% of your own time, and only when that suit is added or removed. The 1% is the middle of that shift. The 2% is the high side of the same year — the men’s 50 m freestyle moved about 2.0% — not a second measurement, and not a promise. Worked example: 100 m in 1:00.00 in a non-textile suit, then a legal textile suit, is about 0.6 to 1.2 seconds slower, so 1:00.60–1:01.20. Knee and shoulder coverage is written beside that band so you can match the rule. It is not what produced the seconds.
Time band
1:00.60–1:01.20
- Seconds on this swim
- about 0.6–1.2 s slower
- Per 100 m
- about 0.6–1.2 s slower
This band exists only because the 2008–2009 non-textile suit came in, or went out. It is the shift in the world’s top times that year, not your next race. Illegal in a World Aquatics pool race: a non-textile suit (the polyurethane suits, out since 1 January 2010), a men’s suit above the navel or below the knee, a women’s suit that covers the neck, goes past the shoulders or below the knee. An open-water wetsuit is a different garment, required below 18 °C. It is not this suit. Rules dated 18 February 2026.
Also swimming, biking and running? Triathlon finish time
1–2% of your time, and only when the non-textile suit is added or removed. In 2008 that generation shifted the mean of the world’s top-10 times by about 1.2% in men’s events and about 1.0% in women’s (Berthelot and colleagues, Materials Today, 2010). 2% is the high side of the same year, not a second measurement on you, and not a second per centimetre of coverage.
How it works
Read the fabric first, then the cut. A textile suit within the cut is the racing suit you can wear in a pool. The polyurethane suits that covered more of the body were banned from pool racing on 1 January 2010. If both of yours are textile, or both are the old non-textile kind, the band is about 0. How far the suit reaches is the eligibility rule. It does not have a measured time of its own.
| Suit | In a World Aquatics pool race |
|---|---|
| Textile, men from navel to knee, women from shoulder to knee | Legal, if it is on the approved list |
| Non-textile, or below the knee, or a men’s suit above the navel, or a women’s suit over the neck or past the shoulders | Not legal. This is the suit swimmers call illegal |
| Open-water wetsuit, at least 3 mm | A different garment. Required below 18 °C, not a pool suit |
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Frequently asked questions
Does each centimetre of suit take seconds off?+
No. A textile jammer and a textile kneeskin can both be legal, and neither one has a known seconds-per-centimetre. The 1–2% band on this page turns on only when the non-textile suit of 2008–2009 is added or removed. Change the cut and leave the fabric class alone, and the estimate is about 0.
Is the 1–2% my next race?+
It is the shift in the world’s top-10 times in 2008, the year polyurethane suits arrived, not a finish time with your name on it. Men’s events moved about 1.2% on average, women’s about 1.0%, and a few events, such as the men’s 50 m freestyle, sat near 2%. Pool, shape and the years between an old race and a new one move the clock by more than the suit.
Which racing suits are illegal?+
In a World Aquatics pool race, under the rules dated 18 February 2026: a non-textile suit, which is the polyurethane generation banned from 1 January 2010; a men’s suit above the navel or below the knee; a women’s suit that covers the neck, extends past the shoulders or goes below the knee; more than two textile layers, or a suit thicker than 0.8 mm, or one that is not permeable. An open-water wetsuit is not this suit. It is required when the water is below 18 °C, and it is at least 3 mm thick.
Why do people compare 2009 times with today?+
Because world records fell in a bunch in 2008 and 2009, and the non-textile suits were banned on 1 January 2010. A time from Rome 2009 and a time from a textile suit years later are not the same race with the suit subtracted. The band on this page is the size of that year’s shift in elite times. It is not a way to rewrite an old result into a new one.
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