How to Measure MMA Headgear for the Perfect Fit

Everything You Need to Know About How to Size MMA Headgear

Walk into any MMA gym and you'll find fighters who measured their shin guards carefully, picked gloves sized to their hand, and then completely guessed on their headgear. They ordered based on a vague sense of their head size, figured it would work itself out, and ended up with gear that shifts on impact, exposes the wrong zones, and becomes one more thing to think about during sparring. It's one of the most consistently overlooked fits in the sport.

Getting headgear sizing right isn't complicated. It requires one specific measurement most fighters skip. This guide covers how to take that measurement accurately, how to read the size chart, what a correct fit feels and looks like in practice, and what to look for beyond size when you're comparing headgear models. Whether you're buying for the first time or you've been tolerating a pair that never quite sat right, this is where to start.

Why Proper Headgear Sizing Matters

Wearing headgear that doesn't fit correctly is almost as bad as not wearing any at all. That sounds like an exaggeration until you think through what headgear is actually supposed to do. The padding in quality MMA headgear, typically microcellular polyurethane foam or multi-layer foam composites, is engineered to absorb and disperse impact energy across specific surface areas. That only works when the padding is in consistent contact with the right zones. When the gear is too loose and rotates on impact, those zones shift. Your orbital padding ends up over your temple. Your temple padding ends up somewhere it wasn't designed to be. You're still wearing the gear. It's just not protecting you the way it should.

Too tight creates a different set of problems. Pressure builds on the temples and crown over the course of a session. Your focus starts splitting between what's in front of you and the dull ache developing at the sides of your head. By round three or four, tight headgear becomes a genuine distraction. And in hard sparring, distractions cost you.

There's also the practical issue of headgear that requires constant adjustment. Any gear you have to reset mid-round is gear that's pulling your attention at the wrong moment. The best headgear fit is the one you forget about entirely once training starts. It sits where it's supposed to, stays there through exchanges, and lets you focus entirely on your training partner.

How to Measure for MMA Headgear

Unlike shin guards, which require two separate measurements, headgear sizing comes down to a single number: head circumference. Get that right and everything else in this guide follows naturally.

What You Need

A soft tape measure. Fabric or flexible plastic measuring tape conforms to the curve of your skull and gives you an accurate reading. A rigid ruler or carpenter's tape won't bend around your head correctly and will give you a number that's off enough to matter. If you don't have a soft tape, a piece of string works fine: wrap it around your head, mark where it meets, then lay it flat against a ruler to get the measurement.

How to Do It

Position the tape just above your ears, wrapping it around the widest part of your head and across the mid-forehead. This is the same reference point used for hat sizing, which is why hat size is a reliable cross-check when reading headgear charts. Keep the tape level all the way around. It should be snug against your head without compressing it. A tilted or loose measurement will put you in the wrong size. Write down your result in both centimeters and inches; most quality size charts include both.

Have a training partner assist if you can. It's harder than it sounds to hold the tape level on your own head while keeping it from shifting. Two seconds of help produces a meaningfully more accurate result.

MMA Headgear Sizing Chart

ONX headgear sizing is built on head circumference and cross-referenced against hat size. Two sizes cover the full range: Small/Medium and Large/X-Large. The chart below shows exactly where each size falls. Both reference points are included because hat size is something most people already know, which makes it a useful sanity check when the tape measure number looks unfamiliar.

How to Choose Between S/M and L/XL

The chart handles most situations clearly. Where fighters tend to second-guess themselves is at the edges and in the overlap range. Here's how to think through each case.

Your measurement falls squarely in one range.

Go with that size. Measuring 55 or 56 cm, you're S/M. Measuring 60 or 61 cm, you're L/XL. The rear lacing handles fine-tuning from there. Don't overthink it.

You're in the overlap zone (57–58 cm).

This is where most of the questions come from. The short answer: if hats and gear have historically felt a bit loose on you, go S/M. If sizing generally runs small on your head shape, go L/XL. Neither choice is wrong at this measurement. Both sizes are designed to work in this range. The lacing system closes the gap.

You have thick or long hair.

Measure with your hair as it normally sits during training. If you train with it pulled back tight, that's the measurement that matters. If you have significant volume when it's down, that extra mass affects fit. When it's close, size up. You can tighten; you can't add material.

You plan to wear wraps underneath.

Some fighters wrap their heads before sparring, particularly in Muay Thai-heavy training environments. If that's your practice, measure with wraps on and factor that into your decision. Generally, that means sizing up one step from where your bare measurement lands.

What a Proper Fit Actually Feels Like

When you put on headgear for the first time, run through this checklist before you take a single shot in it. A correct fit is identifiable before any contact is made.

• Sits level across your brow with no forward tilt
• Does not shift when you rotate your head side to side or shake it
• Peripheral vision is clear and unobstructed on both sides
• No pressure points on the temples or crown
• Chin strap sits snugly under your chin without pulling the gear forward
• Brow padding makes consistent contact across your forehead
• You stop thinking about the gear within 60 seconds of putting it on

That last point is the actual test. Properly fitted headgear should feel immediately natural. If you're aware of it, something is off. Run through a few head movements before sparring: slip left, slip right, roll under a hook. The gear should track with your head, not lag behind or stay where it was while your head moves inside it.

Signs it's too tight.

Pressure builds on the temples or crown within the first few minutes and gets worse over the session rather than fading once the gear warms up. After taking it off, you'll see visible marks pressed into your forehead. Vision may feel slightly compressed from the sides. Start by loosening the rear lacing. If that doesn't resolve it, size up.

Signs it's too loose.

The most obvious tell is rotation on impact. If you take a shot and the gear shifts noticeably, it's too big. You'll also notice it drifting toward your eyebrows over the course of a round even without contact, just from normal head movement. Tighten the lacing first. If it's already maxed out and the gear still floats, size down.

Headgear Fit and Sizing How-To Video

Coach Trevor Wittman walks through exactly how to fit and size the ONX Elite Ultralight Headgear, including what a correct fit looks and feels like and how to use the rear lacing system to dial in the adjustment.

Fitting Tips for Long-Term Use

Sizing is where fit starts. How you maintain and adjust the gear over time is where it either holds up or slowly drifts. A few things worth knowing beyond the initial purchase:

New gear breaks in.

Quality PU leather and impact foam both conform to the shape of your head over the first several training sessions. If a new pair feels slightly firm or stiff out of the box, that's expected, not a defect. Give it four or five real sessions before making any hard sizing decisions. Gear that felt a touch snug on day one often fits exactly right by the end of the second week.

Use the lacing system deliberately.

The rear lacing on quality MMA headgear exists to give you precise fit adjustment that a velcro strap can't provide. Most fit issues that arise after the break-in period can be resolved with small lacing adjustments rather than a full size swap. Tighten incrementally and check the fit after each adjustment. You're looking for snug contact without pinching at the back of the skull. Over-tighten and you'll feel it at the temples first.

Check the chin strap every session.

The chin strap is the most overlooked part of headgear fit. It should be firm enough that the gear can't ride up on impact, but not so tight that it pulls the headgear forward and compresses your sightlines from below. If the gear drifts back over a long session, the chin strap needs to come in. If vision feels compressed from beneath, loosen it slightly. Takes ten seconds to check. Makes a real difference in how the gear performs over a hard round.

Keep the gear dry between sessions.

Pull headgear out of your bag after every training session and let it air out fully before it goes back in. Leaving sweat-soaked gear sealed in a closed bag is one of the fastest ways to break down foam and create a hygiene situation that shortens the useful life of the gear significantly. Wipe the interior with a damp cloth and use a light disinfectant spray. Avoid machine washing unless the manufacturer specifically says it's safe. Gear that's cared for properly will maintain its structure and protective properties for considerably longer.

Key Features to Look For in MMA Headgear

Once you have your measurement and understand your size, the next question is what separates good headgear from the rest. Size gets you in the right range. Build quality determines how the gear actually performs within that range over time.

Padding construction.

The quality of the padding is the most important performance variable in headgear. Look for multi-layer foam construction that absorbs and disperses impact energy rather than simply compressing under it. Microcellular polyurethane foam is the high-performance standard because it maintains its protective properties over time. It resists the flattening that cheaper foam undergoes with repeated use, which means the gear continues to protect the same way in session 200 as it did in session one. Whatever the materials, padding should cover the full brow, orbital, temple, and chin zones without gaps between them.

Coverage without unnecessary bulk.

Full-face coverage and a low-profile design are not mutually exclusive, though they're often treated as a tradeoff. The better headgear designs achieve both through foam engineering rather than sheer padding thickness. You want brow, orbital, temple, and chin padding that covers those areas on impact, and you want a profile that doesn't add unnecessary mass or shift your center of gravity in ways that affect movement. Less bulk also means less rotational force on impact, which has a direct connection to neck strain and concussion risk over high training volume.

Fit system precision.

An adjustable rear lacing system gives you more precision than a velcro strap because you can dial in the fit incrementally rather than jumping between fixed positions. Look for a closure system that lets you tighten symmetrically so the gear doesn't pull to one side. The chin strap should attach at a point that keeps it running parallel to your jawline without pulling the front of the headgear forward.

Outer shell durability.

Premium PU leather is the standard for quality MMA headgear. It's tear and rip-resistant, moisture-resistant, and holds its shape through intense sessions over time. Genuine leather is used in some models and has a longstanding reputation for durability and feel, but requires more maintenance. More important than the material label is the stitching quality at seams in high-contact zones. Double-stitched seams at the brow and orbital areas will significantly outlast single-stitched construction under real training conditions.

Vision field.

Headgear that restricts peripheral vision creates a real problem in sparring. You'll take strikes you didn't see coming not because your reaction was slow but because the gear physically blocked your sightlines. Precision molding around the orbital area, rather than padding that extends toward the nose, is what preserves vision clarity. Test this before committing: put the gear on, stand in front of a mirror, look straight ahead. You should see your full training environment on both sides without moving your head. If you can't, find a different model.

MMA-specific design.

If you're training MMA rather than boxing exclusively, your headgear needs to work on the ground as well as standing. That means no loose flaps or protruding edges that catch during grappling exchanges. The profile should sit close to the head rather than flaring at the sides. A snug fit and clean exterior also reduces the chance of the gear snagging on your training partner during clinch work, takedowns, or ground transitions.

ONX Headgear: Two Lines, Same Sizing System

ONX offers headgear across two lines: the Premium Ultralight and the Precision Line. Both use the same S/M and L/XL sizing system based on head circumference. The construction and intended training use differ. The fit logic is identical.

The Premium Ultralight.

Designed for fighters who prioritize minimal profile and maximum mobility. The low-profile design reduces lateral head movement on impact, which has a direct effect on neck strain and concussion risk during high-volume striking sessions. Built with microcellular PU foam that maintains its compression set resistance over time. It won't flatten or lose effectiveness with repeated use, which matters a lot across a full training camp. The adjustable rear lacing and multi-point fit system lock the gear in place through striking, grappling, and transitions. At $169, it's built for fighters who train seriously and want gear that performs the same way at the end of a long camp as it did at the start.

The Precision Line.

Built for sparring volume. Multi-layer impact-dispersing foam, full brow-to-chin padded coverage, and adjustable closures for fighters who put in a lot of rounds. The durable synthetic PU shell holds its structure through daily training sessions without breaking down at the seams or losing shape. Available in White, Gray, and Black, the Precision Line is designed for athletes who want serious protection with the flexibility to match their gear setup. At $139, it's the more accessible entry point into quality MMA headgear without compromising on the fundamentals that matter.

If you're deciding between the two, the question is training style and emphasis. Fighters who do a high ratio of striking work and want the smallest, most mobile profile available tend to go Premium Ultralight. Fighters who prioritize maximum cushioning across all zones for hard sparring volume tend to go Precision Line. Both use the same sizing system, so your head circumference measurement applies equally to either model.

MMA Headgear Buying Tips

You've got your measurement, you know your size, and you have a clear picture of what to look for in construction. A few final practical points before you make the call:

• Match the gear to your training intensity. Be honest about how hard you're going and how often. A fighter doing three hard sparring sessions a week needs a different level of foam density and coverage than someone doing light technical work twice a week. If you're unsure where you fall, err toward more protection. Gear with more coverage than you need costs you nothing. Gear that doesn't have enough coverage costs you time out of training.

• Quality gear is cheaper long term. A $50 pair that needs replacing every six months costs more over two years than a $150 pair that lasts four. Beyond cost, cheap foam breaks down and stops protecting correctly, often without looking visibly damaged. You don't always know the protection has degraded until you feel it. Invest once and invest right.

• Order two sizes if you're genuinely unsure, and return the one that doesn't fit. If you've measured carefully and still can't decide, many retailers offer flexible exchange policies. Order both, try them in actual training, and return the one that doesn't work. The few extra minutes at checkout are worth getting the fit right the first time.

• Ask your coach and training partners. Your coach has seen most brands and models come through the gym and has real opinions about what holds up. Teammates can tell you how a specific pair has performed over actual training volume: whether the lacing system held, whether the foam kept its shape, whether the sizing ran true. That kind of first-hand information is worth more than any spec sheet.

• Check competition requirements before buying. If you're planning to compete, some promotions and amateur leagues have specific gear requirements. Certain headgear designs may not be permitted in particular formats. Verify before purchasing so you're not surprised on fight night.

• Care for the gear and it will last. Pull headgear out of your bag after every session and let it air dry fully. Wipe the interior with a damp cloth and use a light disinfectant spray. Don't machine wash unless the manufacturer says it's safe. Leaving wet, sweaty headgear sealed in a bag session after session is one of the fastest ways to break down foam and kill the useful life of quality gear. A few seconds of post-session care adds years.