Mare Gestation Calculator – Accurate Horse Pregnancy & Foaling Due Date Tool
Our Mare Gestation Calculator is a quick and accurate tool designed to help horse owners, breeders and equine professionals estimate a mare’s foaling due date, track pregnancy progress, and plan ahead for the safe arrival of a foal.
Using average gestation length and typical foaling ranges, this calculator gives reliable pregnancy estimates for all horse breeds.
Whether you are a first-time breeder or an experienced horse owner, this horse pregnancy calculator makes predicting foaling dates simple, fast and stress-free.
For more helpful tools related to equine care and animal measurements, explore our full collection of online calculators in the category section.
🌟 What Is a Mare Gestation Calculator?
A Mare Gestation Calculator (also known as a horse gestation calculator, foaling date calculator or equine due date calculator) is an online tool that predicts when a pregnant mare is likely to foal based on her breeding or conception date.
Because a mare’s gestation period typically ranges from 320 to 370 days, predicting the exact day can be difficult.
This calculator uses the average horse pregnancy length of 340 days to give:
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The average foaling due date
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The earliest possible foaling date
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The latest potential foaling date
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A reliable foaling window
It ensures you are well-prepared for the arrival of the foal.
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🐴 How to Use the Mare Gestation Calculator
Using the calculator is simple:
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Select the breeding date (the day the mare was covered/inseminated).
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Click the “Calculate Due Date” button.
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The tool will instantly display:
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Average foaling date (340 days)
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Earliest expected foaling date (320 days)
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Latest expected foaling date (370 days)
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This gives you a clear, easy-to-understand estimate of your mare’s due date and pregnancy timeline.
🔎 How the Mare Gestation Calculator Works
The calculator uses standard equine reproductive timelines:
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Average gestation length: 340 days
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Normal foaling range: 320–370 days
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Most mares foal between: 335–345 days
When you enter the breeding date:
✔ The tool adds 340 days to estimate the average due date
✔ It also calculates a realistic foaling range by adding 320–370 days
This method is widely accepted by equine veterinarians and horse breeders across the world.
It gives you a dependable estimate even though every mare’s pregnancy is slightly different.
⭐ Why Use an Online Mare Gestation Calculator?
Using our online mare gestation calculator offers many benefits:
✔ Quick & Accurate Results
Instant due date predictions based on proven equine gestation data.
✔ Helps Plan for Foaling
Proper planning is essential for a mare’s nutrition, veterinary checks and foaling preparation.
✔ Reduces Stress & Uncertainty
Know the expected foaling window and monitor your mare confidently.
✔ Useful for Breeders & Horse Owners
Ideal for stables, breeding farms, riding schools or personal horse owners.
✔ Reliable for All Horse Breeds
Works for Thoroughbreds, Quarter Horses, Warmbloods, Ponies, Arabians, and more.
✔ Free & Easy to Use
No sign-up or complicated steps — just select a date and get results instantly.
❓ Frequently Asked Questions (FAQ)
1. What is the average gestation period of a mare?
The average mare gestation period is 340 days, but normal pregnancies can range from 320 to 370 days.
2. Can a horse foal earlier or later than the calculated date?
Yes. Each mare is different. Some may foal as early as 320 days, while others may go up to 370 days.
3. How accurate is the mare gestation calculator?
The calculator provides highly accurate estimates based on standard equine gestation timelines.
However, the exact foaling date may vary due to genetics, age, health and environmental factors.
4. Do all horse breeds have the same gestation length?
Most horse breeds have similar gestation lengths (around 340 days). Ponies may sometimes have slightly shorter pregnancies.
5. When should I start preparing for foaling?
Begin preparing around 300 days from the breeding date.
Start monitoring closely from 320 days onwards.