Motorcycle Helmet Size Calculator

Enter your head circumference below to find your helmet size instantly, cross-checked against real sizing charts from AGV, Arai, Shoei, HJC, LS2, and more. Helmet sizing isn't standardized across brands — a "Medium" from one manufacturer can run a full size off from another — so getting the number right before you order saves you a return shipment and a helmet that's already too tight by the time you notice on the road.

Find Your Helmet Size

Measure around the widest part of your head, about 1 cm above your eyebrows.

Between two sizes? Go up — helmets compress slightly as they break in. Always try before buying if possible.

Size Chart

Size Circumference (cm) Circumference (inches)

Sizes vary between models within the same brand. Always check the specific model's chart before purchasing.

Reading the chart: match your measured circumference to the closest row, rounding up if you fall between two sizes. Fit also depends on head shape — most Asian-market brands like HJC, LS2, and Shoei are cut for a rounder oval, while European brands like AGV, Arai, and Schuberth run a longer oval. If a helmet feels tight across the forehead and loose at the sides (or vice versa), the size is right but the shape isn't — try a different brand before sizing up or down.

How to Measure Your Head

  1. Use a soft measuring tape (or a piece of string measured against a ruler).
  2. Place it around the widest part of your head — approximately 1 cm above your eyebrows and ears.
  3. Keep the tape level all the way around.
  4. Note the measurement in centimetres.
  5. If your measurement falls between two sizes, choose the larger size.