Smallholding calculators
Tools for small flocks, suckler herds and horse owners. They work from dates and tape measurements you already have, and they say where every gestation length and feeding figure comes from so you can check it.
- Lambing calculatorLambing dates from tupping dates, with a window for each raddle colour.
- Calving calculatorCalving date from the service date, by breed.
- Horse weight calculatorEstimate weight from heart girth and length, and how much forage to feed.
The figures these tools use
| What | Figure | Source |
|---|---|---|
| Sheep gestation | 143 to 147 days, typically 145 | NADIS |
| Cattle gestation | 283 days on average, 279 to 294 by breed | ICBF |
| Horse forage | 2 to 2.5% of bodyweight a day, never under 1.5% | British Horse Society |
Checked on 25 October 2026. How we calculate explains the method behind each tool.