🐎 Mare Gestation Calculator
Estimate the foaling window and map essential broodmare management tasks for healthy mares and foals.
Use the actual ovulation date if tracked; otherwise, use the breeding date from live cover or AI.
Gestation Overview
Mares typically foal between 320 and 360 days. Maiden mares may carry slightly longer.
How to Use This Calculator
Track breeding data
Enter the breeding or ovulation date recorded by your veterinarian or breeding manager.
Review foaling windows
Use the average date and early/late windows to align night watch schedules and foaling alarms.
Coordinate care
Plan vaccinations, deworming, and colostrum testing based on the milestone reminders.
Formula
Foaling Date ≈ Breeding Date + 340 days
Mares can safely foal anywhere from 320 to 360 days. Monitor milk calcium, behavior, and udder development for real-time foaling cues.
Full Description
Accurate foaling forecasts support broodmare nutrition, vaccination schedules, and foal health checks. This calculator combines industry-standard gestation data with milestone reminders to streamline breeding farm workflows.
Weather, daylight length, and individual mare history can influence gestation durations. Keep detailed breeding records to identify patterns and adjust management decisions in future seasons.
Frequently Asked Questions
Why do mares sometimes carry over 360 days?
Extended gestations are common in late-term pregnancies without complications. Veterinary evaluation is recommended if no foaling signs occur after 365 days.
How do I monitor mares close to foaling?
Use milk calcium tests, foaling cameras, and frequent observation for waxing, restlessness, and vulvar relaxation.
Should I vaccinate during pregnancy?
Yes. Core vaccinations and rhino (EHV-1) boosters are typically administered at 5, 7, and 9 months. Consult your veterinarian for a tailored plan.
Does foal sex affect gestation length?
Some studies suggest colts may carry slightly longer than fillies, but the difference is minor compared to individual mare variation.