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Enter the breeding date and, if you want days remaining and progress, a reference date (leave it blank to use today). The calculator adds the typical mare gestation of 340 days to the breeding date, shows the normal 320 to 360 day foaling window, and works out days remaining and progress through gestation. This is a planning estimate only: it does not confirm pregnancy, and a veterinarian should check any animal that passes its window.
A mare bred on 2026-01-01 has an estimated foaling date 340 days later, with a normal window from 320 to 360 days after breeding. Mares are the most variable of common livestock: a foal born at 320 days may need intensive care, while some mares carry healthy foals to 360 days or beyond. Use the wide window for foaling watch, and prepare the foaling stable well before it opens. Use this gestation chart and date estimator for your breeding records.
Start close watching well before the window opens, and prepare a large, clean, well bedded foaling stable with water and a foaling kit. Signs of near foaling include udder filling, wax on the teats, relaxation of the hindquarters and restlessness. Keep the mare calm and observed, and call a veterinarian early if labour stalls, because foaling problems become emergencies fast.
Season, breed, mare age, foal sex and individual variation all move mare gestation more than in other livestock. Colts tend to be carried a few days longer than fillies, and mares can delay birth in stressful conditions. Record breeding dates and foaling dates for every mare, because a mare's own history is the best guide to her next foaling.
About 340 days on average, with a normal range of about 320 to 360 days. Individual animals vary by breed, litter size and condition.
Add the typical gestation length to the breeding date. For a horse bred on 2026-01-01, the estimated due date is horse plus 340 days.
Because healthy births fall across a range, not on one day. Plan your watch period from the window start, and prepare facilities before it opens.
No, it is a planning estimate only. Pregnancy must be confirmed by observation or veterinary examination, and a false pregnancy or wrong breeding date can make the estimate wrong.
About 11 months, or 340 days on average, with a normal range of about 320 to 360 days.
Season, breed, mare age, foal sex and individual variation all move mare gestation, and mares can delay birth in stressful conditions.
Contact a veterinarian promptly, especially if the animal strains without progress, stops eating, looks weak, or has discharge. Do not decide alone that a pregnancy is overdue.
If animals were exposed over several days, run the calculator from the earliest and latest possible breeding dates and use the wider combined window for planning.
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