Work in animal unit months: either how many AUMs your pasture supplies, or how many AUMs your herd demands — using the common 780 lb forage per AUM convention.
Use this for lease AUM math, public-land permits, or a forage-budget cross-check. It is related to — but not the same as — the pasture stocking-rate page, which focuses on animal-units and grazing days from intake.
One AUM is often treated as ~780 lb of air-dry forage (about 26 lb/day × 30 days for a 1,000 lb cow).
Supply: usable forage = acres × yield × utilization%. AUMs = usable lb ÷ lb_per_AUM.
Demand: AUMs = head × AUE × months.
supply_AUMs = acres × yield_lb_ac × (util% ÷ 100) ÷ 780
demand_AUMs = head × AUE × months
Supply: 160 acres, 2,000 lb/acre, 50% utilization, 780 lb/AUM:
Usable = 160,000 lb → 205.1 AUMs. Over 4 months that supports about 51 AU (205 ÷ 4).
Assumptions: 780 lb/AUM unless you change it; utilization is the grazed share, not total growth.
Limits: does not schedule rotations or account for riparian exclusion. Drought years need lower utilization.
Responsibility: lease and permit definitions of AUM may differ — use the agency factor when required.
Stocking-rate page solves animal-units or days from daily intake. This page speaks in AUM supply/demand for leases and seasonal budgets.
Often ~1.3–1.5 AU depending on calf size — check your Extension table. Yearlings are often ~0.7–0.8.
Multiply tons by 2,000 for lb/acre before entering yield.