Horse Weight Tape Calculator

About this calculator

Without access to a livestock scale, an adult horse's body weight can be estimated from two tape-measure readings using the standard weight-tape formula: weight (lb) = (heart girth in inches)² × body length in inches ÷ 330, where heart girth is measured around the barrel just behind the withers and elbows, and body length runs from the point of the shoulder to the point of the buttock. The squared girth term reflects how weight scales with body volume more than with length alone.

This calculator takes heart girth and body length in inches and returns the estimated weight. Horse owners and barn managers use this formula for routine weight tracking and body-condition monitoring between vet visits, and it's especially relied on by anyone needing to dose dewormer or medication by body weight, since under- or over-dosing based on a guessed weight is a common and avoidable mistake.