Enter the covering date to see when your mare is due, the likely foaling window, and the dates to plan scans, vaccinations and the move to the foaling box.
A mare's pregnancy lasts about 340 days on average. The calculator adds 340 days to the covering date. Normal pregnancies vary from about 320 to 370 days, so the due date is the middle of a window rather than a fixed day.
A mare is pregnant for about 340 days on average, roughly 11 months, but normal pregnancies range from about 320 to 370 days.
Add 340 days to the date she was last covered. Treat that as the middle of a window: most mares foal between 320 and 370 days.
EHV-1 vaccination is commonly given at 5, 7 and 9 months of pregnancy, and a flu and tetanus booster about 4–6 weeks before the due date. Agree the timings with your vet.
This is a planning guide, not veterinary advice.
Related: horse age calculator · flu vaccination checker · hay calculator.
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