How to Choose the Right Helmet Size

Why Helmet Size Matters

A motorcycle helmet is only as good as its fit. A helmet that is too large can rotate on your head during an impact, reducing protection and potentially exposing your face or skull. A helmet that is too tight will cause headaches, pressure points, and discomfort that distracts you while riding.

The right size helmet sits firmly on your head without painful pressure. It does not shift when you move your head. The cheek pads make contact with your cheeks, and the top of the helmet sits level, about one centimeter above your eyebrows. Finding this fit starts with accurate measurement.

How to Measure Your Head

Get a Soft Measuring Tape

Use a fabric measuring tape (the kind used for sewing). If you do not have one, wrap a piece of string around your head and then measure the string against a ruler. Do not use a metal construction tape measure.

Find the Widest Point

Wrap the tape around your head at the widest point. This is typically about 1 centimeter (half an inch) above your eyebrows at the front, and around the most prominent part of the back of your skull. The tape should sit level all the way around, not angled.

Measure Three Times

Take the measurement three times and use the largest number. This accounts for slight variations in tape placement. Write down the number in centimeters. This is your head circumference.

Match to a Size Chart

Use the size charts below to find your helmet size. If you fall between two sizes, choose the smaller one. New helmet padding compresses by 15-20% during the break-in period, so a snug new helmet is correct.

Helmet Size Charts

Standard Motorcycle Helmet Sizes

Size	Head Circumference (cm)	Head Circumference (inches)
XS	53 - 54 cm	20.9 - 21.3 in
S	55 - 56 cm	21.7 - 22.0 in
M	57 - 58 cm	22.4 - 22.8 in
L	59 - 60 cm	23.2 - 23.6 in
XL	61 - 62 cm	24.0 - 24.4 in
XXL	63 - 64 cm	24.8 - 25.2 in

Brand-Specific Sizing Notes

KYT Helmets

KYT helmets use an oval-round internal shape that fits most Asian head shapes well. They tend to be true to size.

TT Course / NX Race: True to size
Falcon 2: Runs slightly large
K2 Rider: True to size
NFJ Open Face: True to size

View KYT Helmets →

NHK Helmets

NHK helmets have a round internal shape and tend to run slightly larger than the standard chart suggests.

RX9: Runs 0.5 size large
GP R Tech: True to size
Consider sizing down if between sizes
Thicker cheek pads available

View NHK Helmets →

AGV Helmets

AGV helmets follow European sizing and tend to run narrower, particularly in the cheek area. If you have a round head shape, consider sizing up.

K1 S: Runs narrow in cheeks
K3: Slightly more accommodating
Consider sizing up if round head
Premium interior conforms over time

View AGV Helmets →

How to Check if Your Helmet Fits Correctly

Once you have your helmet, perform these checks to confirm it fits properly:

The Shake Test

Put the helmet on and fasten the chin strap. Grab the helmet with both hands and try to rotate it side to side and front to back. The helmet should move your skin with it, not slide over it. If it rotates freely, it is too big.

The Eyebrow Test

The top edge of the helmet opening should sit just above your eyebrows (about 1 cm). If it sits higher on your forehead, exposing your forehead, the helmet is too small or positioned incorrectly. If it covers your eyebrows, it may be too large or sitting too low.

The Cheek Pad Test

The cheek pads should touch your cheeks firmly but comfortably. You should feel even pressure on both sides. If there are gaps between your cheeks and the pads, the helmet is too large. If the pads push your cheeks uncomfortably into your teeth, it is too small or needs different cheek pads.

The Pressure Point Test

Wear the helmet for 15-20 minutes around your room. A properly fitting helmet will feel snug but should not create painful hot spots or pressure points on your forehead, crown, or temples. Some initial tightness is normal and will ease as the padding breaks in.

The Roll-Off Test

With the chin strap fastened, grab the back of the helmet and try to roll it forward off your head. Then grab the chin bar and try to push it up and back. The helmet should resist both movements. If it rolls off easily, it is too large or the strap is not tight enough.

Common Sizing Mistakes to Avoid

Buying Too Large for Comfort

Many people choose a loose helmet because it feels more comfortable in the store. But a loose helmet offers poor protection and will only get looser as the padding compresses over time.

Measuring Over Hair

Thick hairstyles, braids, or buns will give a misleading measurement. Measure with your hair as flat as possible, or in the style you will wear while riding.

Ignoring Head Shape

Head circumference is not the only factor. Heads can be round, oval, or intermediate. A helmet designed for round heads will not fit an oval head well, even if the size is correct. This is why brand choice matters.

Not Trying the Helmet On

Size charts are a starting point, not a guarantee. Different helmet models from the same brand can fit differently. Always try the helmet on or use a shop that offers free exchanges like Helmet Shop Bali.

Frequently Asked Questions

How do I measure my head for a motorcycle helmet?

Wrap a soft measuring tape around the widest part of your head, about 1 cm above your eyebrows and around the back of your skull at its widest point. Measure three times and take the largest measurement. This circumference in centimeters determines your helmet size.

What if my helmet size is between two sizes?

If your measurement falls between two sizes, choose the smaller size. Helmet padding compresses and breaks in over the first few weeks of use, so a slightly snug new helmet will become a perfect fit. A loose helmet is dangerous as it can shift or come off in a crash.

How should a properly fitting helmet feel?

A properly fitting helmet should feel snug but not painfully tight. It should not move when you shake your head side to side or up and down. Your cheeks should feel light pressure from the cheek pads, and there should be no gaps between your temples and the padding. You should be able to fit one finger between your forehead and the padding.

Do KYT, NHK, and AGV helmets fit differently?

Yes. KYT helmets tend to have a slightly oval-round internal shape that suits most Asian head shapes well. NHK helmets run slightly larger and have a rounder internal shape. AGV helmets follow European sizing and tend to run narrower, especially in the cheek area. Always try before you buy or use our size exchange service.

Can I exchange my helmet if the size is wrong?

Yes. Helmet Shop Bali offers free size exchanges on all helmets. If your helmet does not fit properly, contact us on WhatsApp and we will deliver the correct size and pick up the original. We want every customer to have a perfectly fitting helmet for safety.