♀️ Dog Heat Cycle Calculator
Track estrus timing for breeding plans or spay scheduling. Adjust cycle length to match your dog’s history.
Most dogs cycle every 6 months (approx. 180 days) but can vary from 4–12 months.
Reminder
Every dog is unique. Log heat dates over time for the most accurate predictions and consult your veterinarian for breeding guidance.
How to Use This Calculator
Record previous heat dates
Track the start dates of past cycles to find an accurate average cycle length.
Adjust cycle length
Enter the typical interval between heats for your dog instead of relying solely on the default.
Plan accordingly
Use projected windows to arrange breeding, vacations, or spay appointments.
Formula
Next Heat ≈ Last Heat Start + Cycle Length
Fertile Window ≈ Next Heat + 9 to 14 days
Many dogs experience proestrus (bleeding) before fertile ovulation. Progesterone testing provides more precise breeding timing.
Full Description
Female dogs typically enter estrus every 6 months, though small breeds may cycle more frequently and large breeds less often. Accurate timing helps breeders plan matings and assists pet owners in managing intact females responsibly.
Keep a calendar of heats, behavioral changes, and physical signs such as vulvar swelling or discharge. Unexpected changes in cycle frequency warrant veterinary evaluation.
Frequently Asked Questions
How long does a dog stay in heat?
The entire cycle lasts 2–4 weeks, with fertile days typically occurring around days 10–14.
Can spayed dogs have heat cycles?
No. Spaying removes the ovaries and prevents future cycles. If you notice bleeding after spay, contact your vet.
What signs indicate heat is approaching?
Swollen vulva, increased urination, and behavioral changes often precede visible bleeding.
When should I consult a veterinarian?
If cycles are irregular, absent for over 12 months, or accompanied by unusual discharge or illness.