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Horse Weight Calculator: Tape Method

Quick answer: Estimate a horse's weight with just a measuring tape: measure the heart girth (around the chest) and body length, then apply the tape formula. This calculator handles adults, yearlings, weanlings, and ponies, in kg or lb.

Last reviewed: September 2026

Key facts

  • Heart girth = around chest, just behind front legs.
  • Body length = point of shoulder to buttock.
  • Formula: weight = girth² × length ÷ divisor.
  • Accurate within ~5% for average horses.

Free horse weight calculator: tape method for adults, yearlings, weanlings, ponies.

How to use

  1. Select horse type.
  2. Measure heart girth and body length.
  3. Read estimated weight in kg and lb.

Formula

Weight (lb) = girth² × length ÷ divisor
Adult: 330, Yearling: 280, Weanling: 240, Pony: 300

Worked examples

Adult, 70in girth, 63in length: 70²×63÷330 = 935 lb (424 kg).

Pony, 60in girth, 55in length: 60²×55÷300 = 660 lb (299 kg).

Frequently asked questions

How accurate is the tape method?

Within ~5% for average builds. Very fat or thin horses vary more.

Where to measure girth?

Around the chest, just behind the front legs, over the heart.

Why different divisors?

Body proportions differ by age and type.

Can I use for donkeys?

The formula is calibrated for horses; donkey estimates are rough.

Why weigh my horse?

For feed, medication dosing, and trailer safety.

Tape vs weighbridge?

Weighbridge is most accurate. Tape is good for regular monitoring.

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