How it works
Stocking rate is worked out in animal units (AU). One AU is a 1,000 lb cow, which eats about 26 lb of forage dry matter a day, or 780 lb a month. That month is one animal unit month (AUM). Your pasture's usable forage divided by what your animals eat gives your carrying capacity.
How to use it
Pick the forage level that best matches your land, or ask your local extension office for yields in your county. Only count the share animals should eat: grazing more than about half of the growth weakens the pasture.
Reference chart
| Animal | Animal units (AU) |
|---|---|
| Cow, 1,000 lb | 1.0 |
| Cow-calf pair | about 1.3 |
| Bull | about 1.35 |
| Yearling cattle | about 0.7 |
| Horse | about 1.25 |
| Donkey | about 0.5 |
| Sheep | about 0.2 |
| Goat | about 0.15 |
Frequently asked questions
How many acres does one cow need?
It depends on your grass. On good pasture it's often about 1.5–3 acres per cow for a summer grazing season. On dry rangeland it can be 20 acres or more. Use the calculator with your own acreage and forage level.
How many goats per acre?
On good grass pasture, this method gives roughly 2–4 goats per acre for a 6-month season. Rotational grazing and brush for browsing can raise that. Crowded goats need more parasite control.
What is an animal unit month (AUM)?
The forage one animal unit (a 1,000 lb cow) eats in a month: about 780 lb of dry matter.
What does take half, leave half mean?
Graze about half of the season's growth and leave the rest to protect roots and regrowth. It's the usual starting point for stocking calculations.
Figures are typical values from university extension and breed-association guidance. Estimates only. Individual animals vary — confirm pregnancy and health questions with your veterinarian. Last reviewed 2026-09-18.