Horse Bodyweight Calculator
Estimate bodyweight from heart girth and body length measurements when a livestock scale is not available, then keep a private history in this browser if you choose.
Weight over time
Saved records remain in this browser only. They are never sent to Lazy K or anyone else.
A useful estimate, not a scale.
With measurements converted to inches first, the adult equation is heart girth × heart girth × body length ÷ 330. Oregon State Extension publishes constants of 301 for a yearling and 280 for a weanling. The adult equation is also offered for an adult pony, with a warning that body shape can affect accuracy.
The selected sources do not support one honest error percentage for every breed, condition and body type, so this tool does not manufacture one. Repeatable measurements are most useful for seeing a trend. A scale remains the accurate method.
This estimate is useful for tracking and general management. Use a livestock scale or weight confirmed by a veterinarian when precise dosing matters.
Related: Supplements and conditions.
Sources
- University of Minnesota College of Veterinary Medicine: body measurements
- University of Tennessee Extension: Estimating a Horse’s Weight
- Oregon State University Extension: equine weight calculator
Guidance last reviewed August 24, 2026.