How to Size a Waterproof Motorcycle Suit | Fit Over Your Gear

For the full breakdown, see our best Waterproof Motorcycle Suit guide.

A waterproof motorcycle suit only works when it fits right. Too loose, and wind funnels rain through openings; too tight, and you can’t move or layer properly. The consistent guidance from manufacturers and retailers comes down to one idea: measure your body, not your street-clothes size, while wearing the gear you’ll actually ride in. That means base layers, riding jeans or pants, and any armor or padding. Most riders end up one to two sizes above their normal street size once they account for that gear.

The payoff is a suit that keeps you dry, lets you move, and keeps your armor exactly where it belongs.

Which Measurements Matter Most

Four body measurements decide almost everything about suit fit: chest, waist, sleeve length, and inseam. Industry sizing guides agree that body measurements taken with a flexible tape are the right starting point, and that you should take them over the layers you’ll actually wear rather than over bare skin or street clothes.

• Chest: measure under the arms around the fullest part of the chest; women should use their largest chest dimension.
• Waist: measure around the natural waistline at navel level, not your jeans size.
• Sleeve length: measure from the center back of the neck, across the shoulder, to the wrist bone, with the arm slightly bent as if holding the handlebars.
• Inseam: measure from the crotch to the floor, ideally while wearing your riding boots.

How to Handle Conflicting Size Numbers

When your chest, waist, and inseam point to different sizes, go with the largest size-relevant measurement. Sizing guides consistently recommend this approach because a suit that is slightly roomy can be adjusted with straps or suspenders, while a suit that is too small in one dimension simply will not fit. Some manufacturers also distinguish between suits meant to be worn inside boots and those meant to go over them, so check that detail before choosing a leg length.

Testing the Fit on the Bike

Standing upright in a suit tells you almost nothing. Once the suit is zipped, sit on the motorcycle or adopt a riding posture, close every fastener, and check three things: armor stays centered over your shoulders, elbows, and knees; sleeves and legs do not ride up; and you can reach the bars without pulling the suit tight across the back. Sportsbikeshop’s suit sizing guide stresses that a correct fit should not compromise where your protectors sit — if the suit is too large, the armor drifts off the joints when you stretch into riding position.

The suit should feel snug but not restrictive. Too-short sleeves and inseams are the most common failure points because they pull up in the riding position and expose gaps where rain gets in. If your measurements fall above a chart’s range, go up a size rather than trying to make a marginal fit work.

Common Sizing Mistakes to Avoid

Most improper fits come from the same few habits. Measuring in street clothes instead of riding layers adds slack where you don’t want it. Choosing a suit that’s too loose creates folds that reduce comfort and let wind push water through openings. Relying on jeans waist size instead of an actual waist measurement throws off the whole chart. And skipping the test with boots, back protectors, and gloves installed means you discover fit problems after purchase instead of before.

FAQs

Should I size up for a waterproof motorcycle suit?

Most riders should size up one to two sizes from their street-clothes size, because the suit must fit over riding layers, armor, and padding. The real answer depends on how much gear you wear underneath. Measure your body while fully geared and use that number, rather than assuming a single size adjustment works for everyone.

How should a motorcycle rain suit fit?

A rain suit should be snug but not restrictive, with full range of motion in the shoulders, knees, and elbows. It should not have so much extra fabric that it flaps or bunches, since loose material lets wind push water through openings. Test it on the bike, not just standing, to confirm sleeves and legs don’t ride up.

Do you measure over or under clothes for a motorcycle suit?

Measure over the layers you’ll actually ride in. That means your base layers, riding pants, and any armor or padding you wear under the suit. Measuring over street clothes or bare skin produces wrong numbers because it doesn’t account for the bulk of riding gear.