Horse Pasture Stocking Rate Calculator (Acres per Horse, Grazing Days, Rotation Paddocks)
Work out how many acres your horses need from forage yield, grazing season, utilisation and how much of the diet pasture supplies, or how long a given pasture will carry them; plan rotational paddocks with rest periods and see how much hay makes up the shortfall.
How it works
daily DM per horse = body weight × 2% × pasture share · season need = daily × horses × days · usable forage per acre = yield (lb DM) × utilisation · acres needed = need ÷ usable per acre; days carried = acres × usable per acre ÷ herd daily need · graze days per paddock ≈ rest ÷ (paddocks − 1)
How much land a horse needs depends on how much grass the land grows, how much of it the horse actually eats rather than tramples, and how long the season is — which is why the honest answer ranges from one acre to five. Starting from the horse's dry-matter appetite and the pasture's realistic yield, the calculator gives the acreage required or the days a given pasture will last, the hay to cover any gap, and a rotation plan, since resting paddocks is the single biggest lever on how much forage a field delivers.
Worked example
Three 1,100 lb horses eating 22 lb of dry matter a day each for a 200-day season need about 6.6 tons of pasture. At 3 tons/acre and 50% utilisation each acre supplies 1.5 usable tons, so 4.4 acres — about 1.5 per horse. Six acres carry them 273 days' worth of grazing, so the season is covered with margin; split into four 1.5-acre paddocks grazed a week each and rested three, the stock density while grazing is 2 horses per acre.
Frequently asked questions
How many acres per horse do I need?
On good, managed pasture with rotation about 1–2 acres per horse for a six-month season; on poor or dry land 3–5 or more. Continuous grazing without rest roughly doubles the land needed because horses graze favourites to the ground and ignore the rest.
What is utilisation?
The fraction of the grass grown that a horse actually eats. Horses are wasteful, selective grazers: 30–40% under continuous grazing, 50–60% with a rotation that moves them before they graze below 3 inches and lets paddocks regrow.
When should I move horses to the next paddock?
When the grass is grazed down to 3–4 inches — never lower, which damages the plants and increases parasite pickup — and return when it has regrown to 6–8 inches, typically 3–4 weeks in spring and 5–6 in summer. Mow or drag manure after each move.
Related calculators
Equine figures are planning estimates from common husbandry references (NRC 2007, extension services). Individual horses, forage quality, climate and workload vary — weigh hay, body-condition score regularly and work with your vet, farrier and nutritionist.