Speedo Endurance Jammer Size Chart: How to Find Your Size

Speedo men’s jammers are sized by waist measurement in inches, in even numbers from 24 up. In Speedo’s current US sizing, a size 32 jammer is made for a roughly 32-inch waist and 37.5-inch hips, and a size 34 is made for a 34-inch waist and 39.5-inch hips. If you’re between sizes, most buyers do better sizing up, since the Endurance fabric is built to last rather than to stretch loosely, and an older Speedo chart ran smaller than the current one. Always check the size guide on the exact product page before you order.

Speedo Endurance Jammer Size Chart (US Men’s)

This table uses Speedo’s US size guide for its Endurance+ HyperBoom jammer for sizes 24 to 34, and Speedo’s Dive Jammer chart (converted from centimeters) for sizes 36 to 46.

Sizes 36 to 46 are converted from Speedo’s centimeter chart (for example, size 36 is listed at a 90 cm waist and 104.5 cm hips), so they’re rounded. Speedo may publish slightly different numbers for specific styles, so confirm on the product page.

Speedo Centimeter Chart (Waist and Hips)

If you measure in centimeters, Speedo’s Dive Jammer chart lists:

Speedo Size Conversions: S, M, L and European Sizes

Some retailers list Speedo jammers in international sizes instead of numbers. One retailer’s chart lines up the sizes like this:

Treat this as a guide, since different retailers and regions sometimes label sizes differently.

How to Measure Yourself for a Speedo Jammer

You need a soft measuring tape.

1. Waist: Measure around your navel. Speedo suggests bending to the side to find the dent, which is where your waist is. Keep the tape level and snug but not tight.
2. Hips: Measure around the widest point of your hips and seat.
3. Compare both numbers to the chart. If your waist and hips point to different sizes, go with the larger one, since a jammer needs to fit the hips comfortably.

Should You Size Up or Down?

Speedo’s size guides have changed over time. An older Speedo chart (still shown on some retailer pages) pairs a size 30 with a 32-inch waist, which means those jammers ran a size smaller than the waist number suggests. Under the current US guide, the size matches the waist more directly.

One Amazon reviewer who wears size 33 pants said Speedo’s chart pointed to a size 30, but reviews suggested buying the size that matches your pants size, so he ordered both a 32 and a 34 to try. He liked the Endurance jammers and would buy them again.

A practical rule:

• If you’re right on a size, take that size.
• If you’re between sizes, size up, especially if you prefer a looser, more comfortable fit.
• If you want a racing-style tight fit, stay with your exact size or go down one, but know that this is a personal choice.
• If you’re buying online, pick a store with easy returns and order two sizes if you’re unsure.

What Is the Speedo Endurance Fabric?

Speedo’s Endurance line is made from polyester-based fabric designed to resist chlorine, so suits keep their shape and color longer than standard swimwear. Newer Endurance+ jammers are described by Speedo as quick-drying with high chlorine resistance, and some Endurance+ Max versions are also marketed as resisting sunscreen, oil and pilling. Many versions include a drawstring waist for adjusting the fit.

Because polyester swimwear has less give than nylon and spandex blends, a jammer that is too small can feel restrictive, which is another reason to size up when in doubt. (Speedo’s nylon and elastane suits, like the Dive Jammer, are stretchier.)

What Does a Jammer Fit Like?

A jammer is a swim short that reaches to about the knee, made for lap swimming and training. Compared to a brief, it offers more coverage. Compared to a trunk or board short, it is closer to the body, which reduces drag. Key fit points:

• Waist: Should sit snug with the drawstring tied, without digging in.
• Thighs: Should feel secure with no bunching or gaps.
• Length: Should hit near the knee, and the leg openings shouldn’t ride up.
• Coverage: Some styles include a front lining and others are unlined, so check the product details.

Common Sizing Problems and Fixes

FAQ

What size Speedo jammer should I get?
Match your waist and hip measurements to the size chart for the specific style, and size up if you’re between sizes.

Are Speedo jammers true to size?
Generally close, but some customers recommend buying the size that matches their pants size, and older charts ran smaller than the current ones.

What size is a 32 waist in Speedo jammers?
Under Speedo’s current US guide, a size 32 fits a waist of about 32 inches and hips of about 37.5 inches.

What size is a medium Speedo jammer?
According to one retailer’s conversion, medium corresponds to size 34.

Do Speedo Endurance jammers shrink?
They’re designed to resist chlorine wear and hold their shape, but follow the care label: rinse after swimming and avoid high heat.

Do Speedo jammers have a drawstring?
Many Endurance and Endurance+ styles do, which lets you adjust the waist.

Are jammers supposed to be tight?
They should be snug and secure, but not painful or restrictive.

Is the size chart the same for every Speedo jammer?
Not always. Different styles and years can have slightly different charts, so always check the product page.

Final Thoughts

To find your Speedo Endurance jammer size, measure your waist and hips, match them to the size chart, and go up a size if you fall between two. Since Speedo’s charts differ by style, take a minute to check the guide on the product page before you buy, and choose a seller with easy returns.