FullCalculator

Dog Heat Cycle Calculator

Heat Cycle Prediction

Formula

Average cycle length: Small 180 days, Medium 195 days, Large 210 days, Giant 240 days. Days Until Next Heat = Cycle Length - Days Since Last Heat. Heat stages: Proestrus ~9 days, Estrus (fertile) ~9 days, Diestrus ~60 days, Anestrus (rest) remaining days.

Frequently Asked Questions

How often do dogs go into heat?
Most dogs go into heat every 6-8 months (about twice a year). Small breeds may cycle every 4-6 months, while giant breeds like Great Danes may only cycle once every 8-12 months. It can take up to 2 years for a young dog to develop regular cycles.
How long does a dog's heat last?
The visible heat period (proestrus + estrus) typically lasts 2-3 weeks (about 18 days). Proestrus lasts about 7-10 days with swelling and bleeding, followed by estrus (the fertile period) lasting 5-10 days when the dog is receptive to mating.
At what age do dogs first go into heat?
Small breeds may have their first heat as early as 4-6 months of age, while large and giant breeds may not have their first heat until 12-24 months. Most medium-sized dogs experience their first heat between 6-12 months of age.

You may also need