Horse Weight and Feed Calculator

Step 1 — Measure your horse

Heart girth (cm)

Tape around the barrel just behind the front legs

Body length (cm)

Point of shoulder to point of buttock

Step 2 — Select workload

Maintenance / light At rest, occasional light hacking (under 1 hr/day) Moderate work Regular schooling, trail, or low-level competition (1-2 hrs/day) Heavy work Active competition, daily training, endurance (2+ hrs/day) Breeding / late pregnancy Mares in last trimester or early lactation

How to measure

Heart girth

Use a soft tape measure. Pass it around the horse's barrel immediately behind the front legs, across the withers. Take the measurement at the end of a relaxed exhale. Stand on the near (left) side.

Body length

Measure in a straight horizontal line from the point of the shoulder (the bony prominence at the front of the chest) to the point of the buttock (the bony prominence at the back of the hindquarters).

Formula used

This calculator uses the Carroll and Huntington (1988) formula, the most widely validated weight estimation method for horses and ponies:

kg = (girth cm)² × length cm ÷ 11880

Accuracy is typically within 5-10% of true weight. For medication dosing, always use a verified weight.

Forage figures

Based on NRC (2007) equine nutrition guidelines. Figures represent dry matter intake. Fresh grass contains roughly 20-25% dry matter; hay is approximately 85-90% dry matter. Adjust accordingly.