Women's Health
Use this period date calculator to calculate estimate upcoming period dates from your last period start date, cycle length, and period duration.
Calculator
Cycle estimate
2026-07-03
Expected next period date based on the average cycle length you entered.
Expected next period
2026-07-03
Approximate ovulation
2026-06-19
Fertile window start
2026-06-14
Fertile window end
2026-06-20
Period starts
2026-06-05
Fertile window
2026-06-14 to 2026-06-20
Ovulation
2026-06-19
Next period
2026-07-03
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Expected period date = last start date + cycle length
This calculator applies the formula Expected period date = last start date + cycle length. Enter each value with the matching unit, and AZCalculate updates the result instantly.
Example calculation
The calculator above shows the computed answer instantly from these example values.
Calculator guide
Estimate upcoming period dates from your last period start date, cycle length, and period duration. This page includes an interactive calculator, concise formula notes, worked examples, FAQs, related calculators, and practical guidance you can revisit whenever needed.
We work hard to keep every calculator accurate and useful. If you notice a calculation error, missing option, or unclear explanation, please let us know so we can review and correct it promptly.
See how many people are using this calculator.
Total visits today
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Live users now
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Total saved calculations
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Most active date
2026-06-05
FAQ
It uses Expected period date = last start date + cycle length and calculates the result from the values you enter.
Yes. AZCalculate calculator pages include copy, share, and print actions.
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