Stocking Rate Calculator
Work out grazing days, stocking rate and whether pasture will last.
Please note: Planning figures based on published averages. Soil type, climate, variety, season and local practice all shift these results substantially. Base real decisions on a soil test, local extension guidance and the product label — particularly for fertiliser, lime and any crop protection product, where the label is a legal document.
What the Stocking Rate Calculator does
A grazing budget compares the dry matter a paddock can actually deliver against what the herd eats each day. Only part of the standing cover is genuinely grazeable, and where the pasture is still growing that regrowth offsets demand, extending the days available.
Formula
Grazeable DM = (Cover − Residual) × Utilisation × AreaHerd demand = Intake per head × HeadNet demand = Herd demand − RegrowthGrazing days = Grazeable DM ÷ Net demand
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Grazing area | number | Yes | Accepts more than 0. |
| Grazing area unit | one of 4 options | Yes | — |
| Pasture dry matter available | kg DM/ha | Yes | Accepts more than 0. |
| Utilisation | % | Yes | The share of pasture the animals actually eat rather than trample or foul. |
| Residual to leave | kg DM/ha | Optional | Cover you want remaining after grazing. Accepts 0 or more. |
| Animal class | one of 11 options | Yes | — |
| Number of animals | number | Yes | Accepts 1 or more. |
| Dry matter intake per head | kg DM/day | Optional | Leave at 0 to use the class default. Accepts 0 or more. |
| Pasture growth | kg DM/ha/day | Optional | Accepts 0 or more. |
How to use it
- Choose Grazing area unit and Animal class.
- Enter Grazing area, Pasture dry matter available, Utilisation and Number of animals.
- Optionally add Residual to leave, Dry matter intake per head and Pasture growth.
- Select Calculate.
Worked example
Thirty beef cows on 5 hectares carrying 2,500 kg DM/ha at 70% utilisation.
- Area
- 5 ha
- Cover
- 2,500 kg DM/ha
- Utilisation
- 70%
- Head
- 30
8,750 kg of grazeable dry matter against 900 kg a day of herd demand — 9.7 days of grazing at 6 head per hectare.
Reading the result
- "Net demand per day" (shown once a growth rate is entered) is what actually limits grazing days — regrowth offsets demand rather than reducing total demand, so even a modest growth rate can meaningfully extend the days available.
- The livestock unit columns let stocking rate be compared against regulatory or industry benchmarks on one scale regardless of which species is actually grazing.
Assumptions and limitations
- Pasture cover, utilisation and any entered growth rate are all treated as a static snapshot for the whole grazing-days figure — in practice cover and growth both change as grazing itself progresses.
- Intake per head, when using the class default, is a bodyweight-based estimate — it does not adjust for animal condition or this specific paddock's pasture quality.
Common mistakes
- Leaving "residual" at its default of 0, meaning graze to zero — the notes warn that grazing below roughly 1,500 kg DM/ha slows regrowth, so a rotational system that needs pasture to keep growing back will overstate available grazing days at the cost of future pasture health.
Frequently asked questions
What utilisation should I assume?
70–80% under a tight rotation, 50–60% under set stocking. The rest is trampled, fouled or refused around dung pats.
What is a livestock unit?
A standard animal for comparing mixed stock, where a mature dairy cow is 1.0. A ewe is about 0.1, so ten ewes graze like one cow.