Livestock Pasture Acreage Calculator

Why Stocking Rates Vary So Much

The number of animals a pasture can support depends on grass species, rainfall, soil quality, and how the land is managed. A lush irrigated pasture in the Pacific Northwest can support a cow and calf on half an acre. A dry range in West Texas might need 20 acres for the same animal. The values here are reasonable starting points for improved temperate-zone pasture receiving 30 to 40 inches of annual rainfall.

Continuous vs Rotational Grazing

Continuous grazing keeps animals on the same pasture all season. It is simple but degrades pasture quality over time because animals selectively graze the best plants repeatedly, allowing weeds and bare soil to expand.

Rotational grazing splits the pasture into paddocks (typically 4 to 8), moving animals when grass is grazed down to 3 to 4 inches and resting each paddock until regrowth reaches 8 to 12 inches. The rest period lets grass build root reserves. Well-managed rotational systems can support 50 to 100% more animals on the same land compared to continuous grazing.

Stocking Rate Guidelines

These are for maintained temperate pastures and represent whole-season averages:

Horses are selective grazers and harder on pasture than cattle, which is why they get no better than a cow despite eating less: they crop closer, they graze the same favored patches repeatedly, and they churn wet ground.

Pigs are the exception on this list, and it matters

The pig figures are stocking density, not a feeding plan. Pasture supplies perhaps 10 to 25% of a growing pig’s diet. Pigs are omnivores with a simple stomach, and they cannot extract enough energy from grass to grow on it the way a ruminant does. Any pastured pig still needs grain or equivalent feed daily. What the pasture buys you is rooting behavior, better meat, cleaner ground, and lower feed bills, not free food.

The same caution applies in reverse to goats. Goats are browsers rather than grazers, and a paddock of brush, saplings and briars carries far more goats than the same acreage of grass. If you are clearing scrub, the numbers above understate what the land will hold.

How this differs from the paddock calculator

This page answers “how much land do I need for these animals across a whole grazing season”. The Pasture Rotation Days calculator answers a narrower question: how many days a single paddock of a given size feeds the herd on one pass, before it needs resting. The two use different units on purpose and will not produce matching numbers, because one is a season-long average and the other is a single grazing pass on standing forage.

Always have a drought contingency plan. In dry years, supplemental hay or temporary destocking is far cheaper than reseeding damaged pasture.