Bell Motorcycle Helmet Size Guide

Not sure what size Bell motorcycle helmet you need? Measure your head circumference approximately 2.5 cm above your eyebrows, then compare it with the correct Bell helmet size chart below. Bell sizing varies between models, so don't assume that a Medium or Large in one Bell helmet will fit exactly the same as another.

This guide covers popular Bell motorcycle helmets including the Bullitt GT, Custom 500, Eliminator, Lithium, Qualifier, Race Star DLX, Moto-3, Moto-10 and several motocross and adventure models. We've grouped helmets that share the same measurements to make finding your size easier.

Bell Motorcycle Helmet Size Charts by Model

Important: Find your helmet model in the groups below before choosing a size. Measurements are in centimetres and relate to head circumference. Always check the fit of your actual helmet before riding.

Bell Bullitt GT, Custom 500, Moto-3 and Other Standard Sizes

The following helmet models share the same general head circumference measurements:

• Bell Bullitt GT
• Bell Bullitt GT Carbon
• Bell Custom 500
• Bell Custom 500 Carbon
• Bell Magnum
• Bell Moto-3
• Bell Race Star DLX
• Bell TX501 / TX-501
• Bell Scout Air (sizes S to XXL)

These models share the same centimetre measurements, although their internal shapes, padding and shell construction can feel different. Not every model is manufactured in every size shown.

Bell Eliminator, Qualifier, MX-9 Adventure and MX-10 Sizes

The following models use the same general measurements as the previous group but include an additional XXXL size:

• Bell Eliminator
• Bell Eliminator Carbon
• Bell Qualifier
• Bell MX-9 Adventure / MX-9 Adventure Mips
• Bell MX-10 Mips
• Bell SRT Modular
• Bell SRT Modular Night Rider

Although these models share the same published measurements, they can have different internal shapes and cheek pads. Always check your exact model's fitting information.

Bell Lithium and Lithium Mips Size Chart

Bell Lithium helmets have an important sizing difference at XXXL. Unlike many other Bell models, the XXXL measurement overlaps with XXL.

This chart applies to:

• Bell Lithium
• Bell Lithium Mips
• Bell Lithium Mips+

Important: Bell lists XXXL as 64–66 cm, overlapping the XXL measurement at 64 cm. If your head measures 64 cm, check the fit of the particular Lithium helmet rather than assuming either size will be correct.

Bell Moto-10 Spherical, Moto-10 Mips and Moto-10 GP Sizes

The Bell Moto-10 range uses different sizing measurements from many of Bell's road helmets. This is particularly noticeable in the Large, XL and XXL sizes.

This chart applies to:

• Bell Moto-10 Spherical
• Bell Moto-10 Mips
• Bell Moto-10 GP

For example, a 60 cm head measurement falls into Large on the standard Bell chart but XL on the Moto-10 chart. Always use the correct model-specific information.

Bell Pit Boss Helmet Size Chart

The Bell Pit Boss uses combined size labels rather than the conventional XS, S, M, L and XL sequence.

These measurements are for the older Pit Boss model. Check the information accompanying your particular helmet, as some retailer size charts show slightly different measurements.

Bell Youth MX-10 Mips Helmet Size Chart

Bell produces separate youth motocross helmets with their own sizing measurements. The Youth MX-10 Mips should not be sized using the adult MX-10 chart.

Children's helmets must fit correctly at the time of use. Never buy a larger helmet simply to leave room for a child to grow.

Bell General Adult Motorcycle Helmet Size Chart

Bell also publishes a general motorcycle helmet size chart. This can be used as an initial reference when researching an older or unlisted model, but it should not replace the specific chart for your helmet.

Important: The general chart has overlapping ranges and is not a substitute for the correct model-specific measurements. If your Bell model isn't listed above, check its manual or the manufacturer's latest guidance before choosing a size.

Source: Bell Helmets official UK size charts. Model-specific measurements take priority over general sizing information.

Why Do Bell Motorcycle Helmet Sizes Vary Between Models?

Bell manufactures several different types of motorcycle helmet, from classic open-face models such as the Custom 500 to modern full-face, flip-front and motocross helmets.

Different helmet models can use different internal shapes, shell constructions and comfort padding arrangements. Some also use slightly different head circumference measurements for the same letter size.

For example, a Bell Lithium and Bell Moto-10 don't use identical measurements across their size ranges. A Large in one model may therefore correspond to a different head circumference from a Large in another.

The correct Bell helmet size depends on the particular model you're buying. Always identify your helmet before using a sizing chart.

How to Measure Your Head for a Bell Helmet

You'll need a flexible tape measure, preferably the type used for sewing. If you haven't got one, a piece of string and a ruler will do the job.

1. Position the tape: Wrap it around your head approximately 2.5 cm above your eyebrows, passing just above your ears and around the widest part of the back of your head.
2. Keep it level: Make sure the tape sits flat against your head without pulling it excessively tight.
3. Measure your head: Record the circumference in centimetres.
4. Check again: Repeat the measurement to confirm the result. Use the larger accurate measurement if the readings differ.
5. Find your helmet model: Identify the relevant Bell size chart above.
6. Choose your starting size: Compare your measurement with the chart and try the helmet on to confirm the fit.

If possible, ask someone to help you measure. It's surprisingly easy to position the tape incorrectly when doing it yourself.

How Should a Bell Motorcycle Helmet Fit?

A properly fitted Bell motorcycle helmet should feel snug and secure without creating painful pressure points. The helmet should move with your head rather than sliding around independently.

• Forehead and temples: The internal lining should make firm, even contact without causing pain.
• Cheeks: On helmets with cheek pads, these should fit snugly against your face.
• Crown: There shouldn't be noticeable gaps between your head and the helmet lining.
• Movement: With the chin strap correctly fastened, gently move the helmet from side to side and up and down. It should stay securely positioned.
• Comfort: Wear the helmet indoors for a while to check whether uncomfortable pressure points develop.

Remember that some Bell helmets may feel different from others even when the size label is identical.

What If You're Between Two Bell Helmet Sizes?

If your head measurement falls between two published sizes, Bell's general guidance suggests trying the larger size as a starting point.

However, that doesn't mean a larger helmet will always fit correctly. The final decision should be based on how securely the particular helmet fits your head.

Try neighbouring sizes wherever possible. A correctly fitted motorcycle helmet should feel snug without painful pressure points or excessive movement.

Don't rely on the comfort padding settling to correct a helmet that's the wrong size or shape.

How Do You Know If a Bell Helmet Is Too Big?

A Bell helmet may be too large if it moves independently of your head, feels loose around the cheeks or slides on with very little resistance.

With the chin strap fastened, gently try moving the helmet forwards, backwards and from side to side. Excessive movement may indicate that the size or internal shape isn't suitable.

Remember that the comfort padding may settle with regular use, so a helmet that's already loose when new isn't a good starting point.

How Do You Know If a Bell Helmet Is Too Small?

A helmet that's too small may cause painful pressure around your forehead, temples or the sides of your head.

Some initial firmness is normal, particularly around the cheek pads, but persistent discomfort isn't something you should simply put up with.

The comfort padding may settle slightly with use, but the protective EPS liner isn't designed to compress to accommodate an incorrectly sized helmet.

For more advice, read our guide to dealing with a tight motorcycle helmet.

Can You Wear Glasses With a Bell Motorcycle Helmet?

Many riders wear spectacles with their Bell helmets, although comfort depends on the model, your glasses and your head shape.

Some Bell models, including the Eliminator and SRT Modular, feature eyewear-friendly interior designs. Even so, it's worth trying the helmet with your usual glasses before buying.

Check that the arms of your glasses don't create uncomfortable pressure around your temples and that your glasses remain correctly positioned.

Our guide to wearing glasses with a motorcycle helmet

Try Bell Motorcycle Helmets at RaceLeathers

A size chart is a useful starting point, but there's no substitute for trying a motorcycle helmet on properly.

At RaceLeathers in Darwen, Lancashire, we can help you check the fit of your motorcycle helmet and find a suitable size and shape.

Visit RaceLeathers at 136 Bolton Road, Darwen, Lancashire, BB3 1BZ. We're open Monday to Saturday, 10am to 5pm.

Get directions to RaceLeathers on Google Maps.

Browse our Bell motorcycle helmets and accessories or explore our complete range of motorcycle helmets online.

Bell Helmet Sizing FAQs

Are Bell motorcycle helmets true to size?

Bell helmets follow the manufacturer's published sizing measurements, but the ranges differ between some models. Always use the chart for your particular Bell helmet rather than assuming your usual size will be correct.

What size Bell helmet do I need for a 58 cm head?

A 58 cm head measurement corresponds to Medium in many Bell models, including the Bullitt GT, Lithium, Eliminator and Qualifier. However, the Moto-10 chart also places 58 cm within Large. Check the chart for your particular helmet.

What size Bell helmet do I need for a 60 cm head?

A 60 cm measurement normally corresponds to Large in many Bell road helmets, but XL in the Moto-10 range. This is why checking the individual model's sizing information matters.

Do Bell Lithium helmets fit differently?

Bell Lithium and Lithium Mips helmets have their own published size chart, including an overlapping measurement between XXL and XXXL at 64 cm. Always check the fit of the helmet rather than choosing solely by the letter size.

Are Bell Bullitt GT and Custom 500 sizes the same?

The Bullitt GT and Custom 500 share the same published head circumference measurements, but their different designs and internal padding may affect how they feel when worn.

Do Bell Moto-10 helmets use different sizing?

Yes. The Moto-10 range uses different measurements from many Bell road helmets. For example, XL covers 60–61 cm in the Moto-10 range compared with 61–62 cm in the Bullitt GT range.

Are Bell youth helmet sizes different from adult sizes?

Yes. The Youth MX-10 Mips has its own size chart covering YS, YM and YL. Always check the correct youth chart and ensure the helmet fits securely rather than buying a larger size for the child to grow into.

Do Bell helmets loosen over time?

The internal comfort padding can compress slightly with regular use, but the protective EPS impact liner shouldn't be expected to change shape to accommodate your head.

What if my Bell helmet model isn't listed?

Bell has manufactured many different motorcycle helmets over the years. If your model isn't listed, check the manufacturer's original manual or current model-specific guidance rather than assuming the general size chart will be correct.

Where can I try Bell motorcycle helmets in Lancashire?

Visit RaceLeathers at 136 Bolton Road, Darwen, Lancashire, BB3 1BZ, for motorcycle helmet fitting advice. We're open Monday to Saturday, 10am to 5pm. Get directions on Google Maps.