Reproductive Health Calculator

Free reproductive health calculator to estimate next menstrual period. Instant results in your browser — no signup.

JavaScript is required for live calculation.

You can still read how Reproductive Health Calculator works, the formula, examples, and FAQs below.

Date
Days to add (+) or subtract (−)

Direct calculator

Inputs

Date

Days to add (+) or subtract (−)

Results update when you click Estimate.

Estimated ovulation

Feb 14, 2026

Days changed

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Recently used

Tools you open will show up here on this device — with your last inputs when available.

What this result means

Free reproductive health calculator to estimate next menstrual period. Instant results in your browser — no signup. Estimate next menstrual period using last period; cycle length. Result: next period date.

Assumptions

Rule dependency: Universal formula.

How it works

Estimate next menstrual period using last period; cycle length. Result: next period date.

Example

Example: “period calculator”. Enter your values and click the button to get a result.

Frequently asked questions

What does this next menstrual period calculator do?+

It helps you estimate next menstrual period. Typical search: “period calculator”.

How should I read the result?+

Estimate next menstrual period using last period; cycle length. Result: next period date.