How to Measure Your Head

Measure your head as shown, around the widest part of your head. This is generally right above your eyebrows and ears. If you plan on wearing a Balaclava (we suggest it), you should measure your head with it on.

We have significantly better results with a flexible tape measure, but if one is not available you can use a string to measure your head, and then transfer that to your measuring device.

Then reference the chart below to find which helmet size you should use. If you fall between sizes (IE if your head measures 56.5 cm) we would recommend using the smaller size.

Please Note:

We have found that customers who had previously worn a 59cm (Large) ST4 helmet are most comfortable in a 60cm (Large Plus) which utilizes the larger shell size.

Helmet Size CM Inches US Hat Size Shell Size
Helmet Size:Extra Small (54cm) Head Size (in CM):53-54 cm Head Size (in Inches):21 - 211/4 Hat Size:65/8 - 63/4 Shell Size:Small Shell
Helmet Size:Small (55cm) Head Size (in CM):55-56 cm Size (in Inches):215/8 - 22 Hat Size:67/8 - 7 Shell Size:Small Shell
Helmet Size:Medium (57cm) Head Size (in CM):57-58 cm Size (in Inches):223/8 - 223/4 Hat Size:71/8 - 71/4 Shell Size:Small Shell
Helmet Size:Large (59cm) Head Size (in CM):59-60 cm Size (in Inches):231/4 - 235/8 Hat Size:71/4 - 71/2 Shell Size:Small Shell
Helmet Size:Large Plus (60cm) Head Size (in CM):60-61 cm Size (in Inches):231/4 - 235/8 Hat Size:71/4 - 71/2 Shell Size:Large Shell
Helmet Size:Extra Large (61cm) Head Size (in CM):61-62 cm Size (in Inches):24 - 243/8 Hat Size:75/8 - 73/4 Shell Size:Large Shell

What to do if your helmet doesn't fit correctly

There are many things we can do to adjust your helmet fit. Obviously the best thing is to go to your local dealer and try on the helmets, but many times in this industry, that is just not possible. One of the great things about Stilo helmets is the adjustability with helmet padding.

Crown Pad

There are a few thicknesses of crown pads available that can help with the fitment of the helmet on the top of your head. These attach via velcro and are fairly easy to swap. If you are upgrading your crown pad, we recommend adding an Eject system if you didn't purchase your helmet with it.

Cheek Pads

The most popular way to adjust helmet fit is with cheek pads. This ability is not unique to Stilo. However, the design of the cheek pads is unique to stilo. The EPS cheek pads offer increase protection in lateral crashes, and are available in four different thicknesses.


Another way you can adjust the fit of the helmet is by using different pads behind your earmuffs. There are two different thicknesses available, and this will help adjust the fitment of the helmet on the side of your head.