Estimate a horse’s weight from heart girth and body length using the standard weight-tape formula, in pounds and kilograms.
Standard weight-tape formula: (girth² × length) / 330, in inches, gives pounds. A tape estimate is not a scale weight; use it for feed and worming guidance. Not veterinary advice: this is an estimate for planning only. Always confirm care, feeding and health decisions with a qualified veterinarian.
Estimated weight (kg)
How to use this tool
Run the tape around the barrel just behind the withers and forelegs, snug but not tight.
Measure from the point of the shoulder to the point of the buttock.
Use inches or centimetres; the tool converts centimetres before applying the formula.
Use it for feeding and dosing guidance, and confirm with a weighbridge or vet when accuracy matters.
Formula & worked example
A horse with a 72-inch girth and 68-inch body length weighs about (72² × 68) / 330 = 1,068 lb, about 485 kg.
Limitations — read this before you rely on it
The tape formula is an approximation: build, breed and condition affect accuracy, and it can be off by 5–10% or more. It is not a substitute for a scale weight for medication dosing or sale. Not veterinary advice: this is an estimate for planning only. Always confirm care, feeding and health decisions with a qualified veterinarian.
Frequently asked questions
Usually within about 5–10% for average horses, less accurate for very fat, thin or unusual builds.
Around the barrel just behind the withers, where a girth strap sits.
It works best for average riding horses; ponies and heavy draughts tend to be less accurate.
Feed rations, wormers and many medicines are dosed by weight, so a good estimate beats a guess.
Yes — monthly tape measurements track condition changes better than a single reading.