A riding helmet is the single most important piece of equipment you own. It is also the one most often bought in the wrong size.
Not because riders don't care — you absolutely do — but because helmet sizing is genuinely more nuanced than most people expect. A helmet that fits correctly should feel secure and snug, with zero rocking or shifting when you move your head. It should not hurt, but it should not feel loose either. That distinction is easy to describe, harder to find without a proper measurement as your starting point.
This guide walks you through exactly how to measure your head at home, how to translate that number into a size, and what to do when the sizing chart doesn't give you a clean answer.
What You Need Before You Start
- A soft fabric measuring tape (the kind used for sewing or tailoring)
- A mirror, or a helper — measuring your own head accurately is harder than it sounds
- A pen and paper to record your measurement in centimeters
If you don't have a fabric tape measure, a piece of string and a ruler work perfectly well.
How to Measure Your Head for a Riding Helmet: Step-by-Step
Step 1: Find the Widest Point of Your Head
Place the measuring tape approximately one inch (about 2.5 cm) above your eyebrows, at the level where the front edge of the helmet will sit. Wrap the tape horizontally around the widest part of the back of your head, passing just above the ears.
This is your hat circumference, and it is the only measurement that matters for helmet sizing.
Step 2: Keep the Tape Level
This is where most people go wrong. The tape should sit parallel to the floor all the way around — not angling up at the back or dipping down over one ear. An uneven tape can throw your measurement off by a full centimeter, which may land you in the wrong size bracket.
Step 3: Measure Twice
Take the measurement twice and write down both numbers. If they differ by more than a few millimeters, take a third measurement. Use the most consistent reading as your size.
Step 4: Record in Centimeters
Riding helmet sizing uses centimeters universally. If your tape reads in inches, multiply by 2.54 to convert. Write your measurement down — you will need it for every helmet brand's sizing chart.
How to Read a Riding Helmet Sizing Chart
Every helmet brand publishes a sizing chart that maps head circumference to their size designations. These differ by brand, which is why knowing your measurement in centimeters matters so much — it gives you a neutral starting point that works across every chart.
What to Do If You're Between Sizes
This is the most common question we receive about helmet sizing, and the answer depends on head shape as much as circumference.
If your measurement falls between two sizes, consider the following:
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Head shape matters. Heads that are rounder (more equal front-to-back and side-to-side) may fit differently in the same size than heads that are more oval. Most premium helmet brands offer oval and round shell options — this is worth knowing before you order.
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Padding adjusts fit. Quality helmets come with interchangeable comfort pads that allow minor fit adjustments. Going up a size and using additional padding is usually preferable to going down and creating pressure points.
- When in doubt, go up. A helmet that is slightly too large can be corrected with padding. A helmet that is too tight creates pressure points, reduces blood circulation, and will never feel comfortable — no matter how long you wear it.
Signs a Helmet Fits Correctly
Once you have a helmet on, here is how to assess the fit before purchasing:
✓ It sits level on your head — not tilted back to expose your forehead, not pulled down over your brow bone. The brim should sit approximately one to two finger-widths above your eyebrows.
✓ It does not rock side to side or front to back — place your hands on either side and try to move the helmet gently. If it shifts independently of your scalp, it is too large.
✓ It feels snug but not painful — there should be even pressure around your head, not pinching in one spot or space in another. A slight sense of compression is correct. Headache-inducing tightness is not.
✓ The harness sits correctly — the chin strap should form a V-shape below each ear, and you should be able to fit no more than one finger between the strap and your chin when fastened.
✓ It passes the shake test — once the chin strap is properly fastened, shake your head gently from left to right. If the helmet moves independently of your head, the strap needs further adjustment. If it stays put, you're good. Once properly fitted and closed, the helmet should not be removable without unfastening the strap.
Brand-Specific Sizing Notes
All three helmet brands we carry — Kask, KEP Italia, and FreeJump — use the same fundamental two-step approach: you first select a shell based on your general head circumference range, then choose an individual liner insert that matches your exact measurement. This system gives you a more precise fit than a single-size helmet, but it means you have two decisions to make. Here is how each brand's system works.
Kask Helmet Sizing
Kask uses three non-overlapping shell sizes. Once you know which shell you are in, you select the liner insert that matches your centimeter measurement exactly.
| Shell | Head Circumference Range |
|---|---|
| S | 52–56 cm |
| M | 57–59 cm |
| L | 60–63 cm |
Kask shells do not overlap — each picks up exactly where the last ends. If your measurement is 57 cm you are in the M shell; 60 cm puts you in the L. Select the liner within that shell that matches your centimeter measurement. If you fall between two liner sizes, round up to allow the padding a little room to compress with wear.
KEP Italia Helmet Sizing
KEP uses two shell sizes and adds a variable the other brands do not: head shape.
Shell sizes:
| Shell | Head Circumference Range |
|---|---|
| Medium | 51–58 cm |
| Large | 59–62 cm |
Liner sizes run from 51 cm to 62 cm at every centimeter. KEP displays sizes in both centimeters and traditional fractional hat sizes (6-3/8, 6-1/2, etc.) — use the centimeter figure for accuracy.
Head shape is the step most people miss. KEP offers two configurations for the Large shell:
- Round — for heads that measure roughly equal front-to-back and side-to-side
- Oval — for heads that are notably longer front-to-back than side-to-side
If you measure in the Large range and are unsure which shape describes you, this is worth a quick call or email before ordering. It is a meaningful fit difference, not a minor one.
One practical note: the KEP interior liner is removable and machine washable at 30°C, so as your liner compresses and conforms to your head over time, you can maintain it properly — another reason to get the liner size right from the start.
KEP also starts at 51 cm, which makes it the right option for riders with smaller head circumferences who fall below the 52 cm starting point of Kask and FreeJump.
FreeJump Voronoï Helmet Sizing
FreeJump brings the same safety-first engineering philosophy behind their automatic-release stirrups to their Voronoï helmet — including a first-of-its-kind temporal protection system designed to protect the most vulnerable area of the skull.
Shell sizes:
| Shell | Head Circumference Range |
|---|---|
| S | 52–56 cm |
| M | 55–59 cm |
| L | 58–62 cm |
Unlike Kask, FreeJump shell sizes overlap at the borders. Measurements of 55 cm and 56 cm exist in both the S and M shells; 58 cm and 59 cm exist in both the M and L shells. If your measurement lands in an overlap zone, you choose the shell that best fits your head shape and pair it with the matching liner. Liners are available at every individual centimeter across the full 52–62 cm range.
The overlap also has a practical benefit: riders who wear their hair differently on different days can swap liners without buying a new helmet — a thoughtful design detail worth knowing.
Helmet Fitting FAQs
How often should I remeasure my head?
Adult head circumference does not typically change, but if you have not measured in years or you are buying a new brand, always re-measure before purchasing. Do not assume your size from one brand transfers to another.
Can I size a riding helmet the same way I size a baseball cap?
No. Baseball cap sizing often uses a looser fit standard. Riding helmets are safety equipment and must fit snugly. Always use your centimeter measurement and the brand's specific chart.
My helmet feels tight right after I buy it — is that normal?
Yes, for many premium helmets. The interior comfort padding compresses slightly over the first several wears and conforms to the shape of your head. Snug is correct at purchase. Painful is not.
Does hair thickness affect my helmet size?
It can, especially for riders who typically ride with thick braids or a large bun. If you always wear your hair up under your helmet, measure with your hair in that style.
What if I buy online and the helmet doesn't fit?
We offer returns on unworn helmets with original packaging. If you are uncertain, reach out before you order — we would far rather help you get the right size the first time than process a return. Email us at orders@dapperhorse.com, call the shop at 845-287-0004, or use the chat box on our website.
Should I replace my helmet after a fall?
Yes, always — even if there is no visible damage. The interior polystyrene that absorbs impact energy can suffer compression or microfractures that compromise its protective effectiveness without any outward sign. No exceptions. This applies even if the helmet was dropped rather than worn during a fall — dropping a helmet from even a low height can destroy the shell and render it unsafe.
How long does a riding helmet last?
For riders who use their helmet daily or several times a week, FreeJump recommends replacing every five years. The production date is printed on the inside of the helmet — check it if you're not sure how old yours is. Lifespan varies depending on how carefully the helmet is maintained and how frequently it is used.
Is it safe to buy a second-hand helmet?
No. A riding helmet is a personal protective device — the internal padding adapts to the shape of one person's head over time, and there is no way to verify the impact history of a used helmet. A helmet that has been dropped, sat on, or involved in a fall may look perfectly fine while offering significantly reduced protection. Always buy new.
The Bottom Line
Getting your head measurement right is a five-minute investment that protects a decision you will live with for years. A correctly fitted helmet is safer, more comfortable, and far more likely to stay in consistent rotation — which is the whole point.
If you have questions at any point in this process, we are here. Email us at orders@dapperhorse.com, call the shop at 845-287-0004, or use the chat box on our website — and of course, you are always welcome to stop by in Brewster. Helmet fitting is one of the things we do best, and we take it seriously.
Shop All Helmets → Email Us for Sizing Help →
Dapper Horse carries Kask, KEP Italia, and FreeJump riding helmets — all shipped from our New York warehouse. Questions about sizing, head shape, or which helmet is right for your discipline? Email us at orders@dapperhorse.com or call 845-287-0004.