Next period
Sample
Average cycle 28 days, last start date
What you get
Projected next period start (tracking aid).
Period Calculator
Project the next one or two period start dates from your last bleed and average cycle length (typically 21–45 days). Stress, travel, illness, and hormones commonly shift cycles, so treat predictions as heuristics. Useful for planning—not a medical diagnosis. Processing stays in the browser.
Period Calculator
YearMonthDay
Next period (estimate)
Jun 29, 2025
Following
Jul 27, 2025
These tools provide general fitness estimates only and are not a substitute for professional medical advice.
How to Use This Tool
- Enter last period start.
- Set average cycle days.
- See next one–two predicted starts.
Features
- Two upcoming cycles preview
- 21–45 day cycles
- Quick copy
Example
Frequently Asked Questions
How accurate is the next period date?
We project from last start + average cycle length. Stress, travel, and hormones shift cycles — treat dates as heuristics.
Is this medical advice?
No. This calculator is for general education and planning only. Always consult a qualified clinician for personal health decisions.
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