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Period Calculator

Forecast upcoming period and ovulation dates using your last period start, cycle length, and bleeding days.

Period forecast

Counted from day 1 to the next day 1

Next period starts

Mon, Jul 13, 2026

Bleeding roughly through Fri, Jul 17, 2026

Next six cycles

#PeriodLikely ovulationNext period
1Mon, Jun 15, 2026 – Fri, Jun 19, 2026Mon, Jun 29, 2026Mon, Jul 13, 2026
2Mon, Jul 13, 2026 – Fri, Jul 17, 2026Mon, Jul 27, 2026Mon, Aug 10, 2026
3Mon, Aug 10, 2026 – Fri, Aug 14, 2026Mon, Aug 24, 2026Mon, Sep 7, 2026
4Mon, Sep 7, 2026 – Fri, Sep 11, 2026Mon, Sep 21, 2026Mon, Oct 5, 2026
5Mon, Oct 5, 2026 – Fri, Oct 9, 2026Mon, Oct 19, 2026Mon, Nov 2, 2026
6Mon, Nov 2, 2026 – Fri, Nov 6, 2026Mon, Nov 16, 2026Mon, Nov 30, 2026

Estimate only — not medical advice

These dates are calendar estimates from average cycle and pregnancy lengths. They are not a diagnosis, not contraception, and not a substitute for clinical care. Talk with a qualified clinician about your situation.

How it works

Enter your inputs in the form. Results update as you change values.

Use the share button when available to copy a link with your current inputs so you can revisit or send the same scenario.

Frequently asked questions

Are these results official advice?
No. Calcuit tools provide estimates for education and planning. Confirm important decisions with a qualified professional.

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