Bike helmets for a 51 cm head

A 51 cm head is 20.1 inches. Of the 53 helmets we track, 27 fit you — and here is the exact size to order in each brand.

27 helmets that fit a 51 cm head

Sorted by price. The size in the third column is the one to order — it is the size whose range is centred closest to 51 cm.

So close

These models miss 51 cm by less than 1.5 cm. Head shape and padding thickness can swing a fit by roughly that much, so they are worth trying on in a shop — but we will not tell you they fit.

Is 51 cm a big head?

No — 51 cm (20.1 in) is at the small end. 51% of the models we track come in a size that small, and several brands only start at 51-52 cm.

See also: helmets for small heads.

Measuring, in one minute

Wrap a tailor's tape (or a piece of string you then measure against a ruler) around your head about 1-2 cm above the eyebrows and above the ears — the widest part. Keep it level and snug, not tight. If you land between two numbers, use the bigger one: a helmet's dial can take up slack, it cannot create room.

51 cm is 20.1 inches. American size charts are usually written in inches, European ones in centimetres, and both describe the same measurement.

Related

• 50 cm head
• 52 cm head
• Size chart, all brands
• Safest helmets (Virginia Tech)