What is the Period Calculator?
Know when your next period is likely to start. Enter the first day of your last period, your usual cycle length and how many days your period lasts, and the calculator predicts the next six periods with estimated ovulation dates – helpful for planning travel, events and exams.
Cycles naturally vary by a few days; if your cycle is very irregular or you notice big changes, speak with a doctor.
How to use the Period Calculator
- Pick the first day of your last period.
- Enter your cycle and period length.
- See your upcoming period and ovulation dates.
Frequently asked questions
What is a normal cycle length?
Anywhere from 21 to 35 days is common for adults.
Why are my dates different?
Stress, illness, travel and weight changes can shift a cycle.
Can I use this to avoid pregnancy?
No – calendar predictions are not reliable contraception.
Is my data stored?
No, nothing is saved.
This period calculator is 100% free, needs no signup and works on phones, tablets and computers. Your data is processed in your browser and never uploaded.
Last updated: · By NodifyTech