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Horse weight calculator

Measure your horse's heart girth and body length with a tape to estimate weight and daily forage.

Tape measure units
All the way round, where the girth sits.

Point of shoulder to point of buttock, one side.

Enter heart girth and body length to estimate weight.

Weighing a horse without a weighbridge

Two tape measurements give a usable weight estimate. The formula is used by Blue Cross and Kentucky Equine Research: heart girth × heart girth × body length ÷ 330, with both measurements in inches, gives the weight in pounds.

How this is calculated

  1. If you measured in centimetres, each measurement is divided by 2.54 to convert to inches.
  2. Weight in lb = girth × girth × length ÷ 330.
  3. Weight in kg = lb × 0.4536.
  4. Daily forage = 2 to 2.5% of the weight (British Horse Society), with 1.5% as the minimum and 1.5 to 2% for weight loss.

Worked example

Bonnie's heart girth is 72 inches (about 183cm) and her body length is 66 inches (about 168cm).

72 × 72 × 66 ÷ 330 = 1,037lb, which is 470kg. At 2 to 2.5% of bodyweight she needs about 9.4 to 11.8kg of forage a day, and never less than 7kg.

Getting a good measurement

Stand the horse square on level ground and keep the tape snug but not tight. Use the same tape and the same spots each time so changes in the result reflect real changes in weight.

Kentucky Equine Research advises asking your vet when you need a precise weight for dosing medicine or supplements.

Questions people ask

How much does a horse weigh?

It depends on height, breed and condition, so measure your own horse. As an example, a horse with a 72 inch heart girth and a 66 inch body length works out at about 1,037lb, or 470kg, using the girth and length formula.

How accurate is the girth and length formula?

Blue Cross says it gives a slightly more accurate result than a weight tape, but a weighbridge is the only truly accurate way to weigh a horse. It is best used to track whether your horse is gaining or losing weight over time. Kentucky Equine Research notes it may be less accurate for ponies and miniature horses.

How do I measure heart girth and body length?

Heart girth: pass the tape all the way round the body where the girth would normally sit. Body length: measure in a straight line from the point of the shoulder to the point of the buttock on one side.

How much hay does a horse need a day?

The British Horse Society recommends roughly 2 to 2.5% of bodyweight a day, and never less than 1.5%. For a horse that needs to lose weight it suggests 1.5 to 2%, and no lower than 1.5% unless your vet says so.

Sources

  1. Blue Cross: How to weigh your horse
  2. Kentucky Equine Research: Weight calculation
  3. British Horse Society: Feeding horses

Figures checked on 25 October 2026. Read how we calculate for the rounding and assumptions behind every tool.