Horse Gestation Calculator

This tool turns a mare's cover date into a foaling date using the 340 day average, which is close enough to eleven months that the two are often used interchangeably. Enter the cover date and it returns the expected date, the normal window from day 320 to day 370, and the ordinary calendar dates along the way: the day 14 scan that can still catch twins, the day 25 heartbeat check, sexing from day 60, the five, seven and nine month marks, and the move to the foaling place at day 300. You can also work backwards from a foaling date you want, or check how far along she is on any given day. The single date is the middle of a fifty day window, not an appointment, so plan around the window rather than the day.