Period Calculator

Predict your next period start date from last period and average cycle length.

Next period starts
Tue, Aug 4, 2026
Expected endSat, Aug 8, 2026
Following cycleTue, Sep 1, 2026

Steps

  1. Enter last period start
  2. Set cycle length
  3. See next period date

Related

Averages vary by person. Not a substitute for clinical guidance.

FAQ

Are results official?

No—quick estimates only.

Is data saved?

No. Calculations run in your browser.