Are you wondering when your pregnant mare will foal? Use our Mare Gestation Calculator to find out! The average gestation length in the mare ranges from 320 to 362 days; most mares will foal within 330-345 days of successful breeding. However, mares have successfully foaled with gestation lengths outside this range.
Please Note: The Mare Gestation Calculator is intended for use only as a foaling date estimation tool for horses. It does not consider differences between individual mares. TheHorse.com is not responsible for problems or injuries arising from the use/misuse of this tool or for any inaccuracy in the foaling date estimate of an individual horse.
Estimated foaling date:
Select a breeding date in the calendar to see the estimated foaling date range.
- This calculator gives a gestation range of 331-346 days from breeding (adding a day for ovulation to a 330- to 345-day range).
- Individual mares tend to have their own gestation length tendencies.
- Ponies, on average, tend to have shorter gestation periods than full-size horses.
- This calculator is not intended for gestation estimation in donkeys or other equids—only horses.