Horse gestation calculator and foaling date planner
Enter the breeding or ovulation date and get the mare's due date, the foaling window and every gestation milestone with a date on it. Or start from the foaling date you want and work back to when to breed.
Gestation calculator: due date and milestones
Counted from ovulation. If you only know the breeding date, use the last breeding; with a fresh or cooled dose that is usually within a day of ovulation.
| Date | Day | Milestone |
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The milestone schedule is the one BreedingPro puts on every mare's record. It is general guidance; your veterinarian sets the exam and vaccination programme for your mare and your region.
Pick a date to see the due date and the milestones.
Foaling date planner: when to breed
Start from the foaling date you want, an early foal for the futurities or a May foal for the grass, and see when the mare needs to ovulate and the window she will most likely foal in.
Pick the foaling date you want to see the breeding date.
From the makers of BreedingPro
Keep the whole season on one record
- Record the breeding once and the due date, milestones and reminders go on the mare's record.
- Heat cycles predicted from the mare's own cycle length, with reminders in the app and by email.
- Ultrasound findings with follicle sizes, edema, fluid, embryo count and heartbeat.
- Frozen semen inventory by stallion, tank, canister and slot; a client portal for mare owners.
Web and iPhone. No card needed for the trial; your records stay readable if it lapses.
Questions
Horse gestation, answered
How long is a horse pregnant?
Most mares foal between 320 and 360 days after ovulation, and 340 days is the usual planning figure. Individual mares, breeds, the season and the sex of the foal all move the date, so treat the due date as the middle of a window, not a deadline. A mare's own past foalings are the best guide to her next one.
Should I count from the breeding date or the ovulation date?
Gestation is counted from ovulation. If your veterinarian confirmed ovulation on ultrasound, use that date. If you only know the breeding date, use the last breeding; with a fresh or cooled dose that is usually within a day of ovulation, with frozen semen it is closer still.
When is the first pregnancy check?
The first ultrasound is usually at 14 to 16 days after ovulation, which is also when twins are found and reduced. A heartbeat is seen from about 25 to 28 days, and many breeders recheck at 45 and 60 days, when the foal's sex can often be determined.
When should a pregnant mare be vaccinated against rhinopneumonitis?
The common schedule is an EHV-1 (rhinopneumonitis) vaccine at five, seven and nine months of pregnancy, with the pre-foaling boosters four to six weeks before the due date so the colostrum carries the antibodies. Your veterinarian sets the programme for your region.
What are the signs that foaling is close?
Udder development from two to four weeks out, waxing of the teats in the last days, relaxation of the muscles around the tailhead, and a change in the milk. Many mares foal at night. Most breeders move the mare to the foaling area and start watching from day 320.
Does BreedingPro do this for every mare automatically?
Yes. Record the breeding and BreedingPro puts the due date, the milestones and the reminders on the mare's record, alongside her heat cycles, ultrasound findings, pregnancy checks and the foaling itself. Every plan starts with a 14-day free trial, no card needed.
Every mare, every cover, every foal
BreedingPro is open now, from $19.99 a month with a 14-day free trial.