Bike & Riding

Helmet Size Calculator: Find Your Bike Helmet Size (cm)

Free tool · Updated October 2, 2026 · By CouponTalk

Your result

Enter your measurements to see your result.

Quick answer

Helmet sizes are based on head circumference measured about 1 inch above the eyebrows. Most brands use 2 cm steps: S is 55–56 cm, M is 57–58 cm, L is 59–60 cm and XL is 61–62 cm. A 57.5 cm head is a Medium. A new helmet should feel snug, with no gap at the forehead, and loosen slightly as the padding settles.

How to measure

Wrap a soft tape around your head about 1 inch above the eyebrows and just above the ears.
Keep the tape level around the widest part at the back of your head.
Measure twice and use the larger number.

Helmet Size Chart

Bike helmet size chart (most brands; check each brand)
Helmet size	Head (cm)	Head (inches)	Head (mm)
XS	53–54 cm	20.9–21.3"	530–540 mm
S	55–56 cm	21.7–22"	550–560 mm
M	57–58 cm	22.4–22.8"	570–580 mm
L	59–60 cm	23.2–23.6"	590–600 mm
XL	61–62 cm	24–24.4"	610–620 mm
XXL	63–64 cm	24.8–25.2"	630–640 mm

Sizes vary between brands by 1–2 cm. Always check the brand's own size chart before you buy.

Frequently asked questions

How do I know my helmet size?

Measure your head circumference 1 inch above your eyebrows. 55–56 cm is Small, 57–58 cm Medium, 59–60 cm Large and 61–62 cm XL in most Indian and international brands.

How should a helmet fit?

It should feel snug all round, the cheek pads should press lightly on your cheeks, and when you shake your head the helmet should not move separately. If it presses painfully on your forehead, try the next size.

What if I am between helmet sizes?

Try both. Brands shape shells differently, so choose the one that is snug without pressure points. Never choose a loose helmet.

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