Cattle Stocking Rate Calculator
Work out how many head a pasture can carry from forage yield, utilization and grazing days — plus acres per animal unit.
How it works
Grazeable DM = acres × yield × utilization · Animal-days = grazeable DM ÷ daily intake · Head = animal-days ÷ grazing days
Stocking rate matches the forage a pasture grows to what a herd eats over the season. Only part of what grows is actually grazed — the rest is trampled, fouled or left as residual — so a utilization factor (often 25–50% for continuous grazing) discounts total production. Dividing grazeable dry matter by daily intake gives animal-unit-days, and dividing that by the number of grazing days gives the head the pasture can carry. One animal unit is a 1,000 lb cow eating about 26 lbs of dry matter a day.
Worked example
100 acres producing 3,000 lbs DM/acre at 50% utilization yields 150,000 lbs of grazeable forage. At 26 lbs/head/day that is 5,769 animal-unit-days; over a 180-day season it supports 5,769 ÷ 180 ≈ 32 head, or about 3.1 acres per animal unit.
Frequently asked questions
What is an animal unit?
An animal unit (AU) is a standardized 1,000 lb beef cow with or without a calf, consuming about 26 lbs of dry matter per day (roughly 2.6% of body weight). Larger cows or those with big calves count as more than one AU, so scale intake up for heavier animals.
Why apply a utilization percentage?
Cattle never eat everything a pasture grows — some forage is trampled, soiled or must be left as residual to protect regrowth and soil. Harvest efficiency for continuous grazing is often 25–50%, while tightly managed rotational grazing can push it higher.
Is stocking rate the same as stocking density?
No. Stocking rate is animals per unit area over the whole season, which this tool estimates. Stocking density is how many animals are on a single paddock at one instant and can be very high during a short rotational graze.
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This calculator is for educational purposes. Double-check important results before acting on them.