Dog Heat Cycle Calculator
First day of last heat
Please select a date.
Typical cycle length (days)
~6 months
~7 months
~8 months
~9 months
~12 months
Average (6 months)
Most dogs cycle every 6-8 months.
Heat duration (days)
Typically 18-24 days.
Breeding date (optional)
If mated, enter date to estimate due date.
Calculate
Results
Next heat starts:
Fertile window:
Due date (if bred):
Formula: Next heat = last heat + cycle length. Fertile window = days 10-14 of heat. Gestation = 63 days from breeding.