When to use
- Dosing dewormers, NSAIDs, or other weight-dependent medications
- Calculating daily feed rations and hay budgets
- Monitoring weight trends over time for health management
- Pre-purchase evaluation or insurance documentation
ToolsConductScience tool
Girth² × Length ÷ 330Free in-browser calculator
Horse Weight Estimator.
Estimate body weight from heart girth and length measurements using the Carroll & Huntington method.
PrivateData stays in your browser
LiveNo sign-up required
Validated2026-04-08
CitableMethods and citation included
Calculator
Results update in placeTry it out
Load example horse weight estimator data to see the full workflow
Measurements
Circumference behind the elbows
Point of shoulder to point of buttock
Correction factor for breed type
Weight Estimate
Weight (lbs)
1,005
Estimated
Weight (kg)
456
Estimated
Breed Factor
×1.00
Quarter Horse
Formula
G\u00B2\u00D7L\u00F7330
Carroll & Huntington 1988
This tool provides an estimate for management purposes (feeding, deworming, medication dosing). It is not a substitute for veterinary assessment. Accuracy is typically \u00B13\u20135% for adult horses when measurements are taken correctly.
Do not use for
- For foals under 2 years — the formula is validated for adult horses
- For pregnant mares in late gestation — fetal weight distorts barrel measurements
Measure on level ground at end of exhale
Heart girth should be taken just behind the elbows and withers at the end of a normal exhale. Body length is measured in a straight line from point of shoulder to point of buttock.
Take 2–3 measurements and average
Single measurements can vary by 20–30 lbs depending on horse posture and tape tension. Averaging multiple readings improves accuracy.
Breed corrections matter
A Draft horse and an Arabian with identical girth and length will weigh differently. The breed correction factor accounts for bone density and frame differences.
1
Method
This tool uses the heart-girth tape method to estimate equine body weight from two measurements: heart girth and body length. The formula ( length) 330 is from Carroll and Huntington (1988). Breed corrections adjust for frame differences. All computation runs locally.
2
Validated
Last validated 2026-04-08. Calculations are designed for planning and documentation support; verify procurement decisions against manufacturer specifications or institutional SOPs.
3
How to cite
How to Cite
ConductScience Horse Weight Estimator (v1.0). ConductScience, Inc. 2026. Available at: https://conductscience.com/tools/horse-weight-estimator
Carroll CL, Huntington PJ. Body condition scoring and weight estimation of horses. Equine Vet J. 1988;20(1):41–45.
Why Body Weight Matters in Equine Care
Accurate body weight is foundational for equine health management. Dewormer dosing, NSAID administration, anesthetic calculations, and feed rations all depend on knowing the horse’s weight. Underdosing dewormers promotes resistance; overdosing NSAIDs risks toxicity. Regular weight monitoring also detects gradual changes — a 50-lb loss over two months may be invisible to the eye but clinically significant.
Frequently asked
325
Free tools
1,200+
Institutions
100%
Client-side
0
Uploads required
Next steps
Equipment
Hay & Forage Calculator
Calculate daily hay needs and yearly bale budgets from estimated weight
Browse EquipmentWater Intake Estimator
Estimate daily water requirements based on weight and conditions
Browse EquipmentHeat Stress Risk Calculator
Assess heat stress risk from temperature and humidity
Browse QuoteNeed help?
Get a quote on equipment or talk to the ConductScience team.
Request quote