Dog Heat Cycle Calculator
Estimate your dog's next heat cycle, fertile window, and due date based on the first day of the last heat or breeding date. Helps pet owners plan and monitor reproductive health.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to Use the Dog Heat Cycle Calculator
- Enter the first day of the last heat – Select the exact date when your dog’s last heat cycle began.
- Choose the typical cycle length – Pick from the dropdown (e.g., 6 months, 7 months, etc.). Most dogs cycle every 6–8 months.
- Set the heat duration – Default is 21 days (typical range 18–24 days). Adjust if needed.
- (Optional) Enter a breeding date – If your dog was mated, provide the date to estimate the due date.
- Click “Calculate” – The results will show:
- Next heat starts – Predicted date of the next heat cycle.
- Fertile window – Best days for breeding (days 10–14 of heat).
- Due date – Estimated delivery date (63 days after breeding, if provided).
Note: All dates are based on the last heat start date and cycle length. Use the date picker for accurate input.
Previous Results
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Frequently Asked Questions
Most dogs cycle every 6 to 8 months, but it can vary by breed and individual. Track the start dates of two consecutive heats to calculate the exact interval.
The fertile window typically occurs between days 10 and 14 of the heat cycle, when the female is most receptive and ovulation occurs.
Dog gestation averages 63 days from the date of breeding, though it can range from 58 to 68 days.