Sheep Gestation Calculator
Planning for lambing season starts with knowing when your ewes are due. Enter the breeding date and sheep breed to calculate the expected lambing date and the window when lambs are most likely to arrive.
Sheep gestation averages about 147 days (roughly 5 months), but it varies by breed from about 142 to 152 days. Prolific breeds with shorter gestations tend to produce more lambs per litter, while breeds with longer gestations often carry singles or twins.
Breed-specific averages:
- Finnsheep: 144 days (prolific, often triplets+)
- Dorset: 145 days
- Suffolk: 146 days
- Hampshire: 147 days
- Merino: 148 days
- Rambouillet: 149 days
- Columbia: 150 days
- Cheviot: 152 days
Factors that influence lambing date:
- Number of lambs: Ewes carrying multiples often lamb 1-3 days earlier than those with singles
- Ewe age: First-time ewes (ewe lambs) may lamb a day or two later
- Nutrition: Proper nutrition in late gestation supports normal timing. Underfed ewes may experience delayed or difficult lambing
- Ram effect: If ewes were exposed to a ram to synchronize breeding, the lambing window will be tighter
Preparing for lambing:
Start watching for signs of labor about 5 days before the expected date. Set up lambing jugs (small pens for individual ewes), stock up on supplies (iodine for navels, colostrum replacer, lamb tubes), and ensure you have a plan for overnight monitoring. Most ewes lamb without assistance, but having everything ready reduces stress for both you and the sheep.