Foal Due Date Calculator

Managing a pregnant mare requires careful tracking of gestation and key developmental milestones. Our Foal Due Date Calculator helps horse owners, breeders, and veterinarians accurately estimate expected foaling dates, monitor pregnancy stages, and plan prenatal care.

Horses have an average gestation period of 340 days (~11 months), though normal pregnancies can range from 320–370 days. This calculator simplifies tracking by providing estimated breeding dates, due dates, pregnancy stages, and important care milestones.

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How to Use the Foal Due Date Calculator

The calculator allows you to estimate foaling dates based on three methods:

1. From Breeding/Conception Date

• Enter the date the mare was bred.
• Select the expected gestation length (early, average, late, or custom).
• Click Calculate to see the estimated foaling date, earliest and latest expected dates, and pregnancy milestones.

2. From Expected Due Date

• Enter the mare’s expected due date.
• The calculator will estimate the breeding/conception date and pregnancy timeline.

3. From Current Days Pregnant

• Enter the number of days the mare has been pregnant.
• Optionally enter today’s date.
• The tool calculates the breeding date, expected foaling date, days remaining, and current trimester.

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Optional Mare Information

You can also enter:

• Mare’s Name
• Breed (e.g., Thoroughbred, Quarter Horse, Arabian)

This information is displayed in the results for easy record-keeping.

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Example

Suppose a Thoroughbred mare was bred on February 1, 2026, with average gestation (340 days):

• Expected Foaling Date: January 6, 2027
• Earliest Expected (320 days): December 26, 2026
• Latest Expected (370 days): February 5, 2027
• Key Milestones:
  • Ultrasound Check: February 15, 2026
  • Heartbeat Detectable: March 17, 2026
  • Mid-Gestation: July 1, 2026
  • Vaccinations: November 28, 2026
  • Foaling Preparation: December 28, 2026

The calculator also indicates the current pregnancy stage (trimester) and days remaining until due date, helping you plan care accordingly.

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Pregnancy Care Recommendations

First Trimester (0–114 days):

• Maintain regular feeding and exercise.
• Ultrasound check at 14–16 days.
• Monitor for early pregnancy loss.

Second Trimester (115–228 days):

• Continue moderate exercise.
• Ensure proper nutrition with high-quality hay and grains.
• Mid-gestation veterinary exam recommended.

Third Trimester (229+ days):

• Increase feed by 15–20% to support fetal growth.
• Reduce strenuous exercise.
• Begin foaling preparation around 300 days.
• Vaccinations at 270 days (rhinopneumonitis, tetanus, etc.).

Pre-Foaling Checklist:

• Prepare clean foaling stall.
• Assemble foaling kit (iodine, towels, lubricant).
• Monitor udder development and waxing.
• Have veterinarian contact ready for emergencies.

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15 Frequently Asked Questions (FAQs)

1. What is the average horse gestation period?
   Approximately 340 days, but can range 320–370 days.
2. Can I use this calculator for any horse breed?
   Yes, it supports all breeds. Breed is optional.
3. How accurate is the expected foaling date?
   It is an estimate; individual mares may vary. Always consult your vet.
4. When should I schedule the first ultrasound?
   Around 14–16 days after breeding.
5. How do I track the pregnancy stage?
   The calculator displays trimester based on days pregnant.
6. Can I enter a custom gestation length?
   Yes, between 280–400 days.
7. What are the key pregnancy milestones?
   Ultrasound, heartbeat detection, mid-gestation, vaccinations, and foaling preparation.
8. Does this calculator track days remaining until foaling?
   Yes, it shows the exact number of days left.
9. Can I enter the expected due date instead of breeding date?
   Yes, it can calculate backwards to find the breeding date.
10. How should I prepare the mare for foaling?
    Clean stall, foaling kit ready, vaccinations up-to-date, monitor behavior.
11. Is it safe to exercise a pregnant mare?
    Yes, light to moderate exercise is recommended. Avoid strenuous activity in late gestation.
12. When should feeding be increased?
    Around the third trimester, increase by 15–20% for fetal growth.
13. Do all mares have the same gestation length?
    No, it varies by breed, age, and individual factors.
14. Can this calculator be used by breeders or vets?
    Yes, it’s designed for both.
15. What should I do if the mare foals early or late?
    Contact a veterinarian immediately for guidance. Early or late births may need medical attention.

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Conclusion

The Foal Due Date Calculator is an essential tool for breeders, horse owners, and veterinarians to estimate foaling dates, track pregnancy milestones, and plan prenatal care. By providing accurate estimates for gestation, days pregnant, and key veterinary checks, this tool ensures mares receive proper monitoring and care throughout their pregnancy.

Using this calculator helps reduce stress, improve foal health, and ensures you are prepared for a safe, well-managed foaling. Always consult your veterinarian for individualized advice and emergency care.