Ovulation date estimate
Explore a rough calendar estimate for a regular menstrual cycle.
How this works
Adds your usual cycle length to the last period start, then subtracts 14 days. This is a simplified assumption, not a measured ovulation date.
Example
Using the example inputs, approximate ovulation date is Oct 15, 2026.
- First day of last period
- 2026-10-01
- Usual cycle length
- 28 days
- Approximate ovulation date
- Oct 15, 2026
Do not use this estimate to prevent pregnancy. Ovulation varies, and calendar dates cannot confirm it.
Scope and assumptions
Educational only. Not reliable for irregular cycles or contraception; discuss fertility questions with a clinician.