Precision Feeding Calculator

This calculator runs on the Animal Unit (AU) system ranchers have used for decades to compare stocking pressure across different animal sizes: one AU is defined as a 1,000-pound cow with calf, consuming roughly 26 pounds of dry matter per day. Your average animal weight is converted to an AU-equivalent (weight ÷ 1000), then multiplied by 26 to get daily dry-matter demand per head. On the supply side, total forage produced is pasture acreage times yield per acre, but only a fraction of that is ever actually eaten — the utilization-rate input accounts for trampling, fouling, and selective grazing, with continuous grazing typically running around 50% utilization versus 60-70% for well-managed rotational systems. Dividing available forage by total herd demand over the grazing season yields maximum carrying capacity, while dividing pasture acres by (herd size × AU-equivalent) gives acres needed per AU at your current stocking rate — the inverse of which is AU per acre, a standard land-productivity benchmark.

Animal Unit Months (AUM), a common billing and lease unit for grazing land, comes from total AU-days divided by 30. The forage-balance percentage compares what's available to what's required, with anything under 100% signaling you're stocked heavier than the pasture can sustainably support at that utilization rate. Feed cost totals forage (valued at your dry-matter cost) plus any supplemental feeding — useful for comparing the true cost of running animals at your current density versus the calculated maximum.