Period Calculator
Estimate your next period
🔒 All data is processed in your browser. Nothing is uploaded to any server.
Quick guide
What can Period Calculator help you do?
Free period calculator. Estimate your next period date and expected period range from last period date, cycle length, and period length.
Best for
Useful for quick file work, text cleanup, calculations, content creation, and website or AI checks.
How to use it
Open the tool, enter or upload what it asks for, then copy or download the result directly.
Privacy and limits
Most tools run in your browser with no sign-in. Very large files or older devices may hit browser memory limits.
Frequently Asked Questions
Can it track irregular cycles?
It estimates from the cycle length you enter. Irregular cycles may vary.
Is my data saved?
No. The calculation runs in the browser.