Period Calculator (Next Period Date)
Predict your next six periods from the first day of your last period and your cycle length.
Result
How to use
- 1
Pick the first day of your last period.
- 2
Set your usual cycle length and how many days your period lasts.
- 3
See your next period dates for the coming six months.
Questions
What is a normal cycle length?
For adults, cycles from 21 to 35 days are considered normal, and a period usually lasts 2 to 7 days. Teenagers can have longer and less regular cycles for the first few years.
Why is my period sometimes late?
Stress, illness, travel, weight change, heavy exercise, PCOS, thyroid problems, breastfeeding and pregnancy can all shift a cycle. If you might be pregnant, take a home pregnancy test.
When should I see a doctor?
See a gynaecologist if your cycles are often shorter than 21 or longer than 35 days, if you miss three periods in a row (and are not pregnant), have very heavy bleeding, bleeding between periods, or severe pain.
About this Period tool
Period Calculator (Next Period Date) — Predict your next six periods from the first day of your last period and your cycle length. It is one of 200 free tools on namasivayam.in, made by software engineer Namasivayam Vadivelan for everyday use in India.
Everything is calculated instantly in your browser: nothing you type or upload is sent to any server, there is no sign-up, and it works on mobile and desktop. Pick the first day of your last period.
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Results are estimates to help you plan. They are not financial, tax or medical advice.