Livestock Stocking Rate Calculator
Stocking rate balances the forage a pasture grows against the forage animals eat. This calculator takes the area in acres, the forage produced per acre, the utilization rate you can safely harvest, the daily dry-matter intake per animal unit, and the number of grazing days, and returns the total usable forage and how many animal units the land can carry. Every agronomic figure is a user-editable input so you can use your own pasture and region data.
Stocking rate formula
Usable forage = acres * forage/acre * (utilization / 100)
Forage per animal unit = daily intake * grazing days
Animal units = usable forage / forage per animal unit
Acres per animal unit = acres / animal units
Usable forage is the dry matter that can be grazed after leaving cover for regrowth. Dividing it by what one animal unit eats over the grazing period gives the number of units the land supports.
Worked example
100 acres growing 3,000 lb/acre, 40 percent utilization, 26 lb/day intake, 180 grazing days: usable forage = 100 * 3,000 * 0.40 = 120,000 lb. Forage per animal unit = 26 * 180 = 4,680 lb. Animal units = 120,000 / 4,680 = 25.64. Acres per animal unit = 100 / 25.64 = 3.90.
Stocking rate: frequently asked questions
What is stocking rate?
Stocking rate is the number of animals or animal units grazing a unit of land over a period of time. A sustainable rate matches the forage an animal consumes to the forage the land produces, leaving enough cover for regrowth. It is usually expressed in animal units per acre or acres per animal unit.
What is an animal unit?
An animal unit (AU) is a standard reference animal, commonly a 1,000-pound cow with calf, used so different livestock can be compared. Daily forage intake is often taken as about 2.6 percent of body weight in dry matter, roughly 26 pounds per day for one AU. This calculator keeps daily intake as a user-editable input.
Why apply a utilization rate?
Not all forage produced should be grazed: a portion must be left to protect the plants and soil. A harvest-efficiency or utilization rate (often 25 to 50 percent for continuous grazing) reduces usable forage accordingly. Enter the value recommended for your grazing system and region.
Official sources
- U.S. Department of Agriculture, Natural Resources Conservation Service: NRCS (grazing lands and forage management).
- The forage-balance method follows from matching forage supplied to forage demanded over the grazing period.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.