Horse weight calculator
Knowing your horse's weight helps you budget feed and dose wormers correctly. Few owners have access to a livestock scale, so this calculator uses the girth-and-length formula Agriculture Victoria publishes. All you need is a soft measuring tape and a helper. Measure around the girth and along the body in centimetres, enter both and get an estimate in kilograms. Weight formulas are approximate, especially for foals, very fit or very fat horses and pregnant mares. Ask your vet to confirm a dose for any medication.
Estimated weight
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Enter girth and length to see an estimate.
Next: work out daily feed from this weight.
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This tool gives an estimate only. It is general information, not veterinary, nutrition, legal or tax advice. Every horse and every situation is different. Check with your vet, equine dentist, farrier or a registered tax agent before you act on the result.
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How to use it
- Stand the horse square on level ground.
- Measure the girth just behind the elbow and withers.
- Measure the body length from the point of the shoulder to the point of the buttock.
- Enter both in cm (or inches).
How it's worked out
Weight (kg) = girth (cm) × girth (cm) × length (cm) ÷ 12,000. Example: girth 190, length 160 → 190 × 190 × 160 ÷ 12,000 = 481.3 kg. 1 in = 2.54 cm.
Questions
- How accurate is a girth tape?
- It's an estimate. Weight estimation "requires a lot of experience", according to Agriculture Victoria.
- Can I use it for wormer doses?
- It helps, but if you're unsure, ask your vet.
- What's a healthy body condition score?
- On the 0–5 scale, letting a horse fall below 2 is likely to compromise its welfare.
- Does it work for ponies and foals?
- Less reliably. Check with your vet.
- Can I enter inches?
- Yes. They're converted to cm (1 in = 2.54 cm).
Sources
Sources checked: 17 Oct 2026.