HealthLive calculator

Period Calculator

Estimate your next period, ovulation date, and fertile window from your cycle pattern.

PeriodMenstrual cycleOvulationFertile window

Calculator Inputs

Configure your scenario
28 days
5 days

Next Period

27 Jun 2026

Expected to end 1 Jul 2026

Ovulation estimate

13 Jun 2026

Fertile window

6 Jun 2026 - 14 Jun 2026

Cycle length

28 days

Period duration

5 days

Cycle insight

These dates are estimates based on a steady cycle. Track actual starts over a few months for better personal accuracy.

Upcoming Periods

Cycle 1

27 Jun 2026 - 1 Jul 2026

Cycle 2

25 Jul 2026 - 29 Jul 2026

Cycle 3

22 Aug 2026 - 26 Aug 2026

Estimate Note

These dates are estimates for planning and education. They do not replace medical advice, diagnosis, contraception guidance, or clinic instructions.

What Is Period Calculator?

The period calculator helps you estimate the main numbers that matter before you commit to a financial decision. It is designed to give a fast, accurate answer while keeping the logic and the core assumptions transparent.

Use this calculator when you want a cleaner breakdown than a manual spreadsheet and when you need consistent Indian number formatting, clear supporting content, and related calculators for follow-up planning.

How To Use This Period Calculator

  1. Enter the required inputs shown in the calculator widget for the period calculator.
  2. Adjust values until the result matches the scenario you want to evaluate.
  3. Review the primary output cards first, then use the supporting explanation and FAQs below for context.

Formula Used In This Period Calculator

This period calculator uses the configured platform formula for the selected scenario and displays the most important variables in plain English.

Refer to the calculator notes and output definitions shown above for the active formula.

  • Each input changes the result in real time.
  • All outputs are formatted for Indian usage and quick comparison.

Example Calculation

A sample period calculator scenario can be tested by entering the default values in the widget above and then adjusting one variable at a time.

That approach makes it easier to see which field has the biggest effect on the final result.

Tips

  • Use realistic values instead of optimistic assumptions.
  • Compare at least two scenarios before making a decision.
  • Review related calculators when your decision affects taxes, affordability, or returns.

Frequently Asked Questions

How is my next period estimated?

The calculator adds your average cycle length to the first day of your last period. The result is an estimate because cycle timing can vary from month to month.

How is the fertile window calculated?

The calculator estimates ovulation as 14 days before the next period, then shows a window from 7 days before ovulation through 1 day after ovulation.

Can this calculator be used as birth control?

No. These dates are only planning estimates and should not be used as contraception or medical advice.