Cattle Body Weight Calculator
When a livestock scale is not available, cattle weight can be estimated from two tape measurements: heart girth around the body just behind the front legs, and body length from the point of shoulder to the pin bone. This calculator applies Schaeffer's heart-girth formula. Measure in inches; the result is in pounds, with a kilogram conversion shown. The divisor is user-editable so you can match the constant for your class of cattle.
Schaeffer's heart-girth formula
Weight (lb) = (girth^2 * length) / divisor
Weight (kg) = weight (lb) * 0.45359237
Girth and length are in inches and the standard mature-cattle divisor is 300. Enter a different divisor for calves or specific breeds where your reference provides one.
Worked example
A steer with a 78 inch girth and 60 inch length, divisor 300: weight = (78 * 78 * 60) / 300 = 365,040 / 300 = 1,216.80 lb. In kilograms: 1,216.80 * 0.45359237 = 551.93 kg.
Cattle weight: frequently asked questions
How is cattle weight estimated without a scale?
Schaeffer's formula estimates cattle weight in pounds as (heart girth in inches squared, times body length in inches) divided by 300. Heart girth is measured around the body just behind the front legs; body length runs from the point of shoulder to the pin bone.
Why is the divisor 300?
300 is the constant in Schaeffer's classic heart-girth equation for mature cattle when measurements are in inches and weight is in pounds. Different references use slightly different constants for calves or specific breeds, so the divisor is a user-editable input here.
How accurate is a girth-and-length estimate?
For typical mature cattle in normal body condition, tape and girth-length estimates are usually within roughly 5 to 10 percent of scale weight. Accuracy falls for very thin, very fat or pregnant animals. Use a calibrated scale for sale or dosing where possible.
Official sources
- U.S. Department of Agriculture: National Agricultural Library (livestock weight reference).
- The pound-to-kilogram factor 0.45359237 is the exact international pound definition (NIST).
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.