Ovulation Calculator
Pinpoint your fertile window and most likely ovulation day so you know the best days to try to conceive. Just enter your last period and cycle length.
Estimates for a regular cycle. Ovulation timing varies — tracking basal body temperature or using ovulation tests gives a more personalized picture.
How it works
An egg survives for about 24 hours after ovulation, but sperm can live for up to five days inside the body. That’s why the days leading up to ovulation matter just as much as ovulation day itself. Together they make up your six-day fertile window.
Frequently asked questions
When am I most fertile? +
Your fertile window is the five days before ovulation plus ovulation day itself — six days in total. The two days before ovulation are typically the most fertile.
When do I ovulate? +
Ovulation usually happens about 14 days before your next period. On a 28-day cycle that’s around day 14, but on a 32-day cycle it’s closer to day 18. We calculate it from the cycle length you enter.
How can I confirm ovulation? +
Tracking your basal body temperature, watching for changes in cervical mucus, or using ovulation predictor kits (OPKs) gives a more personalized picture than calendar estimates alone.
Related reading
- Guide
How to Track Ovulation (BBT, OPKs & Cervical Mucus)
Track ovulation with three simple methods — basal body temperature, ovulation predictor kits and cervical mucus — and combine them to find your fertile window.
Jun 3, 2026 · 5 min read Read more → - Guide
Basal Body Temperature: How to Chart It (and What It Tells You)
Charting your basal body temperature confirms when you ovulated. Here’s how to measure BBT correctly, what the post-ovulation rise looks like, and its limits.
May 30, 2026 · 5 min read Read more → - Guide
How Long After Your Period Do You Ovulate?
On a 28-day cycle you usually ovulate around day 14 — about a week after your period ends. How to find your own ovulation day, whatever your cycle length.
May 30, 2026 · 5 min read Read more → - Guide
How Long Does It Take to Get Pregnant?
Most couples conceive within a year — about 8 in 10 within 12 months, and many sooner. What’s typical, what affects how long it takes, and when to seek advice.
May 30, 2026 · 5 min read Read more → - Guide
How Many Days After Ovulation Does Implantation Happen?
Implantation usually happens 6–10 days after ovulation. Here’s the full timeline, the signs to watch for, and when you can take a pregnancy test.
May 30, 2026 · 5 min read Read more → - Guide
How to Use Ovulation Test Strips (OPKs)
Ovulation tests detect the LH surge 24–36 hours before you ovulate. When to start testing, how to read the result, and how to time things right.
May 30, 2026 · 5 min read Read more → - Guide
Signs of Ovulation: How to Know When You’re Most Fertile
The most reliable signs of ovulation — from cervical mucus to a temperature shift — and how to pinpoint your most fertile days when trying to conceive.
May 30, 2026 · 5 min read Read more →
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