Sheep Gestation & Lambing Date Calculator
Plan your lambing season. Enter the breeding date to estimate when your ewes are due to lamb.
How this calculator works
This calculator takes the date your ewe was bred (or when the ram was turned in) and adds the average gestation length for sheep to predict the lambing date.
Formula used
Expected Date = Breeding Date + Gestation Length (usually 147 days)
Example calculation
If bred on October 1st, adding 147 days gives an expected lambing date of February 25th.
What to do with this result
Mark the expected date on your calendar, and use the 'earliest date' to know when to start checking ewes or preparing lambing jugs.
Ready to track this for the whole flock?
One-off calculations are great for quick checks, but farm decisions are better when records are connected. HerdDeck Shepherd connects sheep records, weights, treatments, and feed costs in one easy app.
Try the DemoFrequently Asked Questions
The average sheep gestation period is roughly 147 days, or about 5 months.
Since ewes can lamb slightly early or late, a ±7 day window provides a safer range for preparation.
Yes. Breed, number of lambs carrying, and age can affect the exact day.
Take the day the ram was introduced (or observed mating) and add 147 days.
Yes, some breeds like Finnsheep may lamb around 142 days, while heavier meat breeds may go closer to 150 days.