How to Measure Your Horse for a Fly Mask: Finding the Perfect Fit

A fly mask can only do its job if it fits correctly.

Too small, and it may rub, restrict movement, or sit too close to the eyes. Too large, and it can shift, sag, or give flies access to the areas it's supposed to protect.

At Kensington, we've learned that one of the biggest reasons horses remove fly masks—or owners become frustrated with them—is simply choosing the wrong size.

The good news? Getting the right fit is easy when you know what to measure. Every one of our fly masks has a measurement guide on our product listing in the graphics, which makes it easy to find your perfect fit.

Why Proper Fly Mask Fit Matters

A properly fitted fly mask should:

• Stay clear of the eyes
• Allow full visibility
• Remain secure during turnout
• Provide complete coverage
• Prevent rubbing and pressure points
• Keep flies from reaching sensitive areas

That's why Kensington fly masks are designed with generous eye clearance, breathable materials, and multiple sizing options to accommodate a wide variety of head shapes.

Before ordering, we recommend taking a few quick measurements.

What You'll Need

• A soft measuring tape
• A helper (optional but useful)
• A horse willing to stand still for a few minutes
• A notebook or phone to record measurements

Measure in inches for the most accurate comparison to our size chart.

Understanding the Kensington Fly Mask Measurements

Our sizing system uses five key measurements, labeled A through E.

Measurement A: Poll to Nose

Measure from the top center of the poll (between the ears) down the center of the face to the point where the mask will end.

This measurement helps determine the overall length of the mask.

Measurement B: Head Circumference

Measure around the horse's head, starting near the poll and wrapping underneath the jaw.

This determines how much room the mask has around the head and cheeks.

Measurement C: Nose Circumference

Measure around the horse's nose at the location where the lower portion of the mask will sit.

This measurement helps ensure a secure yet comfortable fit around the muzzle area.

Measurement D: Ear Length

Measure from the base of the ear to the tip.

This is especially important if you're purchasing a fly mask with ear coverage.

Measurement E: Nose Length

Measure from just below the eye area down to the desired endpoint of the nose coverage.

This is particularly important when selecting a mask with extended nose protection.

Choosing Between Sizes

Not every horse falls perfectly into a sizing chart.

If your measurements fall between sizes, consider your horse's individual head shape.

Consider Sizing Up If:

• Your horse has a broad forehead
• Your horse has prominent facial bones
• You prefer additional eye clearance
• Your horse is between measurements

Consider Sizing Down If:

• Your horse has a refined head
• Measurements consistently fall into the smaller size category
• Your horse is narrow through the jaw and muzzle

When in doubt, compare multiple measurements rather than relying on just one.

Breed Guidelines (But Don't Rely on Them Alone)

While every horse is unique, these general guidelines may help:

Medium Often Fits:

• Arabians
• Smaller Quarter Horses
• Morgans
• Smaller gaited breeds
• Ponies requiring horse-sized masks

Large Often Fits:

• Most Quarter Horses
• Paint Horses
• Thoroughbreds
• Appaloosas
• Average Warmbloods

X-Large Often Fits:

• Large Warmbloods
• Draft Crosses
• Draft Breeds
• Horses with broad heads

Remember: head shape matters more than breed.

We've seen Quarter Horses wear X-Large masks and Draft crosses wear Large masks.

Always measure first.

Signs Your Fly Mask Fits Correctly

After putting the mask on, check for these indicators:

✓ Mesh remains clear of the eyes

✓ Horse can blink normally

✓ No rubbing around the cheeks or jaw

✓ Ears sit comfortably inside ear covers (if applicable)

✓ Nose coverage sits where intended

✓ Mask stays in place during turnout

✓ Horse appears comfortable and relaxed

Signs the Mask May Be Too Small

• Mesh touching the eyes
• Tightness around the jaw
• Ear covers pulling downward
• Excessive rubbing
• Difficulty fastening closures

Signs the Mask May Be Too Large

• Sagging around the face
• Shifting during turnout
• Gaps around the cheeks
• Mask rotating sideways
• Nose coverage extending too far

Finding the Perfect Kensington Fly Mask

Whether you're choosing an Open Top Fly Mask, a fleece-trimmed model, a mask with ears, or a long nose UV-protective style, proper sizing is the foundation of comfort and protection.

Taking just a few minutes to measure can help ensure your horse gets the full benefits of:

• Fly protection
• UV protection
• Better visibility
• Improved comfort
• Reduced rubbing
• A more secure fit

Because the best fly mask in the world only works if your horse wants to wear it.

And a proper fit is where that comfort begins.