🐄 Cattle per Acre Calculator
Determine sustainable stocking density to balance forage supply and livestock demand.
Adjust for grazing system and residual forage goals.
1 AU ≈ 1,000 lb cow with calf. Adjust for stocker weights.
Typical cows consume 2.6% of body weight as dry matter.
Instructions
Measure forage productivity
Sample pastures or use NRCS estimates for dry matter yield per acre.
Set utilization goals
Choose an efficiency percentage reflecting residual and trampling losses.
Adjust for animal size
Scale the animal unit to average cow weight or stocker size for accurate results.
Formula
Usable Forage (lb) = Acres × Yield × Utilization%
Monthly Demand (lb) = AU Weight × Daily Intake × 30
Animal Units = Usable Forage ÷ Monthly Demand
For continuous grazing, adjust demand to match your planned grazing season length instead of 30 days.
About This Tool
Proper stocking prevents overgrazing, maintains soil health, and ensures consistent weight gains. Combine forage estimates with rainfall, rest periods, and soil fertility plans.
Recalculate after drought, fertilization, or changes in herd size to stay ahead of pasture limits.
Common Questions
What is an animal unit?
Typically 1,000 lb cow-calf pair. Adjust for bulls, heifers, or stockers by weight.
How do I gather forage yield numbers?
Clip-and-weigh samples, use pasture probes, or rely on local extension estimates.
Does rotation change utilization rate?
Yes. Intensive rotational grazing often achieves 60–70% utilization, while continuous may be 35–50%.
Should I include hay feeding?
If supplementing with hay, reduce grazing demand accordingly when calculating stocking.