What Is a Pasture Rest Period Calculator?
In rotational grazing, the rest period is how long a paddock is left alone to regrow before animals return to it. Rest it too little and plants never rebuild their root reserves, leading to thinning stands and weed pressure. Rest it too long in fast-growing conditions and you waste grazing days and let forage go to stem. This calculator turns your measured graze-down height, target regrowth height and daily growth rate into a concrete rest-day estimate.
It also estimates the minimum number of paddocks your rotation needs so every paddock gets its full rest period before the herd cycles back to it.
How to Read Your Results
Recommended Rest Period
The number of days a paddock needs to regrow from your graze-down height back up to your target height, based on the growth rate you measured.
Growth Needed
The height difference the forage has to make up — a simple sanity check on your two height entries.
Full Rotation Cycle
Rest days plus the days animals actually spend grazing each paddock — this is the total length of one full trip around all your paddocks.
Minimum Paddocks Needed
The smallest number of paddocks that lets every paddock finish its full rest period before the rotation brings animals back to it. More paddocks than this minimum gives you scheduling flexibility, especially when growth rates slow down.
Real-World Example
A paddock grazed down to 3 inches, with a target regrowth height of 8 inches, growing at 0.3 inches per day, with 3 grazing days per paddock:
| Item | Value |
|---|---|
| Growth needed | 5.0 in |
| Recommended rest period | 16.7 days |
| Full rotation cycle | 19.7 days |
| Minimum paddocks needed | 7 |
If growth slows to 0.15 inches per day later in the season, rest time roughly doubles to about 33 days — which is exactly why growth rate should be remeasured through the season rather than assumed constant.
Tips for Managing Rest Periods
- Re-measure growth rate regularly — spring, summer and fall growth rates on the same pasture can differ by 2-3x.
- Leave enough residual leaf area at graze-down so plants can photosynthesize and regrow quickly.
- Build in extra paddocks beyond the calculated minimum for flexibility during droughts or growth slumps.
- Watch the plants, not just the calendar — height and leaf stage are better rest-period signals than a fixed number of days.
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Last updated: August 2026 · Reviewed by: Simple Calculator Tools Editorial Team