Horse Weight Calculator: Estimate Your Horse Weight

Estimate your horse weight from girth and body length, the proven weight-tape method.

How the weight formula works

This uses the standard adult-horse formula: weight in lbs = (heart girth² × body length) ÷ 330. Heart girth is measured around the barrel just behind the withers and elbows; body length is from the point of the shoulder to the point of the buttock. It is an estimate, but far more accurate than guessing.

How to measure

• Use a soft measuring tape with your horse standing square.
• Heart girth: wrap snugly around the barrel just behind the front legs.
• Body length: from the point of the shoulder to the point of the buttock.

Why knowing weight matters

Accurate weight is essential for safe deworming and medication dosing, and for feeding the right amount. Most horses eat 1.5 to 2.5 percent of body weight in forage daily. Use body condition scoring alongside this number.

Healthy weight tips

• Check body condition monthly; you should feel ribs without seeing them.
• Adjust feed for workload and season.
• Ask your vet before deworming, as dose depends on accurate weight.

Frequently asked questions

How accurate is a weight tape estimate?

Within roughly 10 percent for most adult horses, which is good enough for feeding and dosing decisions.

Why do I need my horse's weight?

Dewormers and medications are dosed by weight, and feeding amounts are a percentage of body weight.

How much should a horse eat?

Generally 1.5 to 2.5 percent of body weight in forage per day, adjusted for workload.

Does this work for ponies and foals?

The formula is designed for adult horses. Use a vet's guidance for foals and very small ponies.

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General guidance only, not a substitute for professional veterinary advice. For health, dosing, or feeding concerns, consult your vet.