DelaDela Tools · runs on your device
Period calculator
Your next three periods, estimated from the dates and lengths you enter.
Your dates
Average cycle lengthDays from one period start to the next
Period lengthDays of bleeding
Enter your details to see your estimate.
Your estimate
Enter your dates to see an estimate.
Next period—· estimated
The one after—· estimated
And the next—· estimated
This calculation repeats the same cycle length. Real cycles can vary, so the dates may change.
How this is calculated
Each estimated period starts one cycle length after the last: start + cycle length × n, lasting your period length. The Dela app can use the history you record rather than only one cycle length. Read about its approach in our methodology.
An estimate, not medical advice. Never use calendar estimates as contraception. If your cycle changes suddenly or worries you, speak with a clinician.