Horse Weight Calculator
Estimate a horse's weight from its heart girth and body length.
About the Horse Weight Calculator
Measure the heart girth and body length with a soft tape, in inches or centimetres. The calculator estimates the horse's weight with the weight-tape formula.
The widely used weight-tape formula estimates weight as heart girth² × body length ÷ 330 (inches → pounds), or ÷ 11,880 using centimetres for kilograms. It's useful for dosing wormers and feeding when no scale is available; it's less accurate for foals, ponies, heavy draught breeds and pregnant mares.
The formula
Weight (lb) = girth² × length ÷ 330; weight (kg) = girth² × length ÷ 11,880 (cm)
Worked example
Heart girth 75 in, body length 65 in
- 75² × 65 ÷ 330
- = 1,108 lb (503 kg)
Questions people ask
How do I measure accurately?
Use a soft tape, keep it level, and measure the same way each time.
How much should a horse eat?
About 1.5–2.5% of body weight in forage dry matter per day.