Holistic Planned Grazing Calculator
Design a rotational grazing paddock plan based on herd size, forage availability, and recovery period goals.
About this calculator
This calculator turns Allan Savory's holistic planned grazing principles into a concrete paddock layout. The core logic works backward from how long you want each paddock to rest: number of paddocks is your target recovery period divided by your planned grazing period per paddock, plus one extra paddock so the herd always has somewhere to move while the rest are recovering. Total pasture acreage is then split evenly across that paddock count. From there, stock density (Animal Units per acre while grazing) falls out of herd size divided by paddock size — the metric Savory-style grazing tries to push high, since dense, short-duration grazing more closely mimics the mob behavior of wild herds and improves manure distribution and hoof impact.
The forage math assumes a fixed daily dry-matter demand of 26 lbs per Animal Unit, checks that against how much forage each paddock can offer (yield per acre times your utilization rate — the "take half, leave half" convention defaults to 50%), and reports both how many days that paddock could sustain the herd and the surplus or deficit versus your planned grazing period. A negative forage balance is your signal that either paddocks are too small, the herd too large, or the grazing period too long. Keep in mind these are static, single-cycle estimates: real forage yield swings with season, rainfall, and prior grazing history, so use the sustainable-days and forage-balance outputs as a planning checkpoint to revisit each rotation, not a fixed year-round number.
Inputs
Results
Number of paddocks
31
How to Use This Calculator
- Enter Total pasture (acres), Herd size (Animal Units), and Grazing period (days/paddock).
- Set Recovery period (days), Forage yield (lbs DM/acre), and Utilization rate (%).
- Review the Number of paddocks result.
- Use Paddock size (acres) and Stock density (AU/acre) to inform your decision.
How the result changes with Grazing period (days/paddock)
| Grazing period (days/paddock) | Number of paddocks |
|---|---|
| 1 | 61 |
| 1.5 | 41 |
| 3 | 21 |
| 5 | 13 |
What each input means
- Total pasture (acres)
- Total grazing acreage to be divided into paddocks.
- Herd size (Animal Units)
- Total herd in Animal Units. 1 AU = 1,000 lb animal. 1 cow-calf pair = ~1.3 AU.
- Grazing period (days/paddock)
- Days the herd stays in each paddock. Short durations (1-3 days) mimic natural mob behavior.
- Recovery period (days)
- Days a paddock rests before re-grazing. Longer in dry climates (60-90+), shorter in humid (30-45).
- Forage yield (lbs DM/acre)
- Standing forage dry matter per acre per grazing cycle. Typical: 2,000-4,000 lbs for temperate grassland.
- Utilization rate (%)
- Percentage of standing forage to be consumed. 'Take half, leave half' = 50%.
What each result means
- Number of paddocks
- Paddocks needed to achieve the target recovery period.
- Paddock size (acres)
- Size of each individual paddock.
- Stock density (AU/acre)
- Animal units per acre during grazing. Higher density = more even grazing and hoof impact.
- Sustainable grazing (days)
- Maximum days the paddock forage can sustain the herd. Should exceed your planned grazing period.
- Forage surplus/deficit (%)
- Positive means surplus forage; negative means the paddock is too small or herd too large.
- Full rotation cycle (days)
- Total days to rotate through all paddocks once.
- Max carrying capacity (AU)
- Maximum animal units each paddock can support for the planned grazing period.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersTotal pasture (acres) = 200, Herd size (Animal Units) = 50, Grazing period (days/paddock) = 2, Recovery period (days) = 60 = 6 input(s) provided
- Calculate Number of paddocksNumber of paddocks = ceil(numPaddocks)31 = 31
- Calculate Paddock sizePaddock size = totalAcres / numPaddocks6.45 = 6.45
- Calculate Stock densityStock density = herdSizeAU / paddockAcres7.75 = 7.75
Engine last updated . Checked against 3 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does the number of paddocks come out to (recovery days / grazing days) + 1?
The extra paddock ensures the herd always has somewhere fresh to move into the moment one paddock finishes its rest, so grazing never has to wait on recovery. If recovery takes 60 days and each paddock is grazed for 2 days, you'd need 30 paddocks cycling through rest, plus one more so a paddock is always ready — 31 total.
What does a negative forage balance percentage mean?
Forage balance compares the forage available in a paddock (yield per acre times your utilization rate) against what the herd will actually eat during the planned grazing period (herd size in Animal Units times 26 lbs dry matter per day times grazing days). A negative number means that paddock can't sustain the herd for the full planned grazing period, so you'd need to shrink the herd, shorten the grazing period, or enlarge the paddock.
What is an Animal Unit and why does the calculator use 26 lbs of dry matter per day?
An Animal Unit (AU) is a standardized livestock reference equal to a 1,000 lb animal; a typical cow-calf pair counts as roughly 1.3 AU. The calculator assumes each AU eats 26 lbs of forage dry matter daily, a commonly used livestock nutrition figure, to translate your herd size into a daily forage demand it can compare against paddock supply.
How is 'sustainable days' different from my planned grazing period?
Sustainable days is how long the forage actually available in a paddock (after applying your utilization rate) could feed the herd before running out, found by dividing available forage by daily demand. It should equal or exceed your planned grazing period — if it's lower, the herd risks depleting that paddock's forage before you move them to the next one.
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