Motorcycle Helmet & Gear Size Guide
Measure your head, use model-specific helmet size charts, and check the fit of your riding gloves and jacket.
How to measure your head
One number, your head circumference in centimetres, is where every helmet size starts. Use a soft fabric tape measure. A rigid steel tape will read too high because it can't follow the curve of your skull.
How to measure
- Use a soft fabric tape measure, not a rigid ruler.
- Route the tape around the widest part of your head, usually about 2.5cm above your eyebrows.
- Pass the tape above your ears on both sides.
- Wrap it around the widest part of the back of your head, the bump you can feel.
- Keep the tape level. Take 2 to 3 readings. Use the largest number.
- Record in centimetres, then check the chart for the exact helmet model.
Measuring over a ponytail or bun inflates the number. Pulling the tape too tight gives a too-small reading. Skipping the back-of-skull bump is the most common error. Don't trust your hat size or the number inside your last helmet. A Shoei M and an AGV M are not the same helmet.
Head shape matters as much as size
Head circumference gives you a starting size. The helmet's internal shape also affects whether it fits comfortably and securely. The three shapes below are broad fitting terms, not exact diagnoses. Interior shape varies by model and market, so use these only as clues and try the specific helmet on.
Pressure at the temples with extra room at the forehead and back may point to a rounder fit. Treat this as a clue only: fit varies by person and by model.
How to check your shape: A top-down photo with your hair flattened can offer a rough clue. The better check is to wear the exact helmet indoors for a short period and note any persistent pressure points. Even, snug pressure is the aim; pain, numbness or a clear hot spot suggests trying another size or shape.
"Asian fit" is a marketing term, not one universal helmet shape. Population research has found average head-shape differences between groups, but there is wide individual overlap. Do not assume a Japanese or Asian-market helmet will be rounder: check the exact model and market version, then try it on.
Helmet size chart
All measurements are in centimetres. This is a general starting reference only. Size boundaries can vary by brand, model and market, so the official chart for the exact helmet takes priority.
| Size | Head (cm) |
|---|---|
| XS | 53 to 54 |
| S | 55 to 56 |
| M | 57 to 58 |
| L | 59 to 60 |
| XL | 61 to 62 |
| XXL | 63 to 64 |
| 3XL | 65 to 66 |
These ranges are not a substitute for the manufacturer chart supplied with the exact model.
Do not automatically size up or down by brand. Check the exact model's chart and fitting instructions, then try both sizes where possible. Choose the size that gives secure, even pressure without pain or a persistent hot spot.
Break-in. What changes, what doesn't.
A helmet normally has an energy-absorbing liner and separate comfort padding. They do different jobs.
If the shell and crown fit are still correct but the cheeks feel loose, a compatible thicker cheek pad may help. Pad options vary by model; ask us what's available and still follow the helmet maker's replacement guidance.
When to replace your helmet
This is general guidance drawn from manufacturer and safety-body advice, not a warranty or a fixed expiry date. An unused helmet stored well may last longer, and a heavily used one less. When in doubt, have it checked or replace it. Sources are listed at the foot of this page.
What a correctly-fitted helmet feels like
Persistent pain, numbness or a clear pressure point during an indoor try-on suggests the size or internal shape may be wrong. A helmet that moves independently of your skin or can roll forward with the strap fastened may be too large or the wrong shape. Do not rely on break-in to correct these problems; try another size or model.
Motorcycle glove sizing
Measure your dominant hand's circumference behind the knuckles, across the widest part of the palm, excluding the thumb. Make a relaxed fist. Check both hands and size to the larger number.
| Check | What to do |
|---|---|
| Measurement method | Use the method named on the exact model chart; some charts use palm circumference, others use hand length. |
| Both hands | Measure both and use the larger result unless the manufacturer says otherwise. |
| Between sizes | Follow that model's recommendation or try both. Do not convert sizes by brand nationality. |
Letter sizes and measuring methods differ between models, including within the same brand. Do not automatically size up for a Japanese brand. Match your measurement to the chart supplied for the glove you are buying.
Some leather gloves ease with wear, but the amount depends on the leather, lining, panels and model. New gloves should feel snug without pain, numbness, bunched material or restricted control movement. Textile and mesh gloves may also have limited give depending on their construction, so do not rely on any glove stretching into the right size.
For Singapore's climate: compare ventilation, protection and fit for your usual ride. Waterproof-membrane gloves can feel warmer but are useful in rain; ventilated gloves are cooler but are not automatically waterproof. Choose based on the product's stated features rather than the material name alone.
Motorcycle jacket sizing
Wear the base layer you normally ride in. Wrap the tape around the fullest part of your chest, under your armpits and across your shoulder blades, parallel to the floor. Also check waist, sleeve and height measurements where the model chart provides them.
| Check | What to look for |
|---|---|
| Chest and waist | Compare both measurements with the exact model chart; do not choose by usual T-shirt size. |
| Sleeves | In riding posture, sleeves should cover the wrists without pulling tightly at the shoulders. |
| Armour position | Shoulder and elbow protectors should remain centred over the intended areas as you move. |
| Layers | If you will wear layers underneath, try or measure with those layers on. |
- Cut varies by model, even within one brand. Race, touring and casual cuts can fit differently, so do not apply one size-up rule to every Dainese or Italian jacket.
- Do not group Scoyco with Japanese brands. Scoyco is a Chinese brand, and RS Taichi, Komine and Scoyco each use their own charts. Check the exact model instead of automatically sizing up.
- Wide, tall or short variants are model-specific. Where offered, follow that manufacturer's chart because modifier letters are not universal.
An excessively loose jacket may let its protectors move away from the intended position. For more airflow, choose a more ventilated design and use the jacket's fit adjusters while keeping the armour properly placed.
Check armour placement in riding posture. Zip the jacket fully and lean forward with your arms slightly bent. Shoulder and elbow protectors should remain centred over the areas they are designed to cover. If they move significantly away, try the adjusters, another size or another model.
Check what protection is actually included. Armour type and certification level vary by jacket, and a back-protector pocket does not mean a certified protector is supplied. For an upgrade, choose a compatible protector in the correct size and verify the certification shown on its label.
Good to know & sources
This guide is general educational information, not a fitting or medical assessment. Every head and every helmet is different, so use it as a starting point and, ideally, try a helmet on before you buy. Always follow the fitting, care and replacement instructions that come with your specific helmet. Where they differ from anything here, follow the manufacturer.
Helmets are safety equipment with a limited service life. Replace yours after any crash or significant impact, and in line with the manufacturer's stated replacement interval, even if it still looks fine.
Selected sources for the fit and helmet-life guidance above:
- SHOEI, helmet care, drops and replacement (about 5 years of normal use): shoei-europe.com/faq
- Arai, helmet lifespan & replacement guidance: whyarai.co.uk/support/faqs
- Snell Memorial Foundation, helmet FAQ (replace after impact; 5-year guidance): smf.org/faq
- HJC, helmet usage and replacement (3 to 5 years depending on use): hjchelmets.us
- RevZilla / Common Tread, how to buy and size a motorcycle helmet (break-in of comfort padding): revzilla.com
- Arai, the three head shapes (long / intermediate / round oval): araiamericas.com
- Ball et al., “A comparison between Chinese and Caucasian head shapes,” Applied Ergonomics 41(6), 2010: sciencedirect.com
