Horse Weight Calculator
Estimate your horse, pony, foal or donkey’s weight from simple tape measurements — no scales needed. Uses the Caroll & Huntington formula with feed rations and worming dose output.
Horse Weight Estimator
Measure heart girth and body length, enter below
Different types use adjusted formula constants for greater accuracy
Tape around barrel just behind the elbow, snug but not tight
Point of shoulder to point of buttock in a straight line
Estimated Weight
Based on heart girth & body length measurements
Enter your horse’s heart girth and body length measurements, then click Estimate Weight to see the calculated weight, feed rations and wormer dose.
Typical Weights by Breed Type
Average weight ranges for common horse and pony types. Individual animals vary — use measurements for accuracy.
| Breed / Type | Typical Weight (kg) | Typical Weight (lbs) | Heart Girth Range | Notes |
|---|---|---|---|---|
| Miniature / Shetland pony | 70–150 kg | 154–330 lbs | 90–130 cm | Use pony formula |
| Native / Dartmoor pony | 150–250 kg | 330–550 lbs | 130–160 cm | Stocky build; use pony formula |
| Cob / Highland pony | 250–450 kg | 550–990 lbs | 160–190 cm | Can vary widely |
| Thoroughbred | 450–550 kg | 990–1,210 lbs | 175–195 cm | Lean build; use horse formula |
| Warmblood (sport horse) | 500–650 kg | 1,100–1,430 lbs | 185–210 cm | Most common sport horse type |
| Irish Draught | 550–700 kg | 1,210–1,540 lbs | 195–220 cm | Heavy bone; use horse formula |
| Shire / Clydesdale | 700–1,000 kg | 1,540–2,200 lbs | 215–245 cm | Use heavy draught formula |
| Standard donkey | 180–320 kg | 396–705 lbs | 115–155 cm | Use donkey formula |
Horse Weight FAQ
Everything you need to know about measuring and estimating horse weight accurately.
You can estimate a horse’s weight without scales using the Caroll and Huntington formula: Weight (kg) = (Heart Girth cm² × Body Length cm) ÷ 11,877. Measure the heart girth (circumference around the barrel just behind the elbow) and the body length (from point of shoulder to point of buttock). This method is accurate to within 5–10% for most horses and is widely used by equine vets and nutritionists.
The most widely validated formula for adult horses is the Caroll and Huntington formula: Weight (kg) = (Heart Girth² × Body Length) ÷ 11,877, where measurements are in centimetres. For ponies, a separate formula accounts for their stockier build using a divisor of 12,000. For foals under 6 months, a heart-girth-only formula is often used. This calculator applies the correct formula based on your selected horse type.
Measure the heart girth by passing a soft measuring tape around the horse’s barrel, starting just behind the withers on one side, passing under the belly just behind the elbow, and back up to the starting point on the other side. Keep the tape snug but not tight, and measure while the horse is standing square on a level surface. Take the measurement after a normal exhale for the most consistent result.
Body length is measured in a straight horizontal line from the point of shoulder (the bony prominence at the front of the shoulder) to the point of buttock (the bony prominence at the rear of the hindquarters). Use a rigid measuring stick or a soft tape held straight — do not follow the curve of the body. The horse should be standing square on level ground.
Knowing your horse’s weight is essential for accurate feed rations (forage and hard feed are typically given as a percentage of body weight), correct dosing of wormers and medications, monitoring body condition changes over time, and managing weight-related health conditions such as laminitis and Equine Metabolic Syndrome. Most veterinary drug doses are given per kg of bodyweight, making an accurate weight estimate critical for safe treatment.
An average light horse breed (Thoroughbred, Warmblood) weighs between 450–600 kg (990–1,320 lbs). Heavy draught breeds such as Shire and Clydesdale typically weigh 700–1,000 kg (1,540–2,200 lbs). Native pony breeds range from 150–350 kg (330–770 lbs) depending on type. Donkeys range from 80–480 kg depending on size. Regular weight checks help detect gradual changes that are difficult to spot by eye.
A healthy weight varies greatly by breed and type. The best guide is a Body Condition Score (BCS) of 4–5 out of 9 on the Henneke scale for most horses. At a healthy weight, you should be able to feel but not see the ribs, the spine should not be prominent, and there should be no cresty neck or fat pads. Regular weight tracking (weekly or fortnightly) is more informative than a single reading.