When is my next period? Work out the date in 10 seconds
Next period: Friday, November 13
That’s in 18 days.
- Fri, Nov 13 – Tue, Nov 17
- Fri, Dec 11 – Tue, Dec 15
- Fri, Jan 8 – Tue, Jan 12
- Fri, Feb 5 – Tue, Feb 9
- Fri, Mar 5 – Tue, Mar 9
- Fri, Apr 2 – Tue, Apr 6
🔒 Calculated in your browser. Nothing you type is sent or stored. Estimates only: cycles vary.
Take the date your last period started and add your usual cycle length. If it started on 8 October and your cycles run about 30 days, your next period is due around 7 November. Expect it within a few days either side: that's normal. The calculator above gives the exact date and how many days are left.
How to calculate your next period by hand
You don't need an app for a quick answer, just two numbers: the first day of your last period and your usual cycle length (days from one period's first day to the next). Then:
- Find the first day of real bleeding last time. Spotting before it doesn't count.
- Add your cycle length in days. On a calendar, count forward that many days, with the start day as day 0.
- The day you land on is your expected period. Circle the two or three days either side too.
| Last period started | Usual cycle | Next period due |
|---|---|---|
| 3 October | 26 days | 29 October |
| 8 October | 28 days | 5 November |
| 8 October | 30 days | 7 November |
| 15 October | 33 days | 17 November |
Don't know your cycle length? Look back at your last three or four start dates and use the cycle length calculator to find your average. If you have no history at all, 28 days is a reasonable first guess, but only a guess.
The calculator above runs in your browser. It shows your next period date, how many days away it is, and the following five periods too. Nothing you enter is sent or stored.
Why your period might not arrive on the day
Period dates move because ovulation moves. The days after ovulation (the luteal phase) stay fairly steady at about 12 to 14 days, but the days before it can stretch. Anything that delays ovulation delays your period by the same amount.
- Stress, poor sleep, travel across time zones or a busy month
- Illness, even a bad cold, around the middle of your cycle
- Big changes in exercise, eating or weight
- Coming off hormonal contraception, breastfeeding, PCOS, thyroid conditions and perimenopause
- Pregnancy, if you've had sex since your last period
A cycle that's a few days longer or shorter than usual is normal. Adult cycles commonly vary by up to 7 days without anything being wrong. If your period hasn't come and you're counting the days, the period late checker tells you how late you are and what to do next.
Signs your next period is close
Your body often gives clues in the last week of the luteal phase. Breast tenderness, bloating, spots, cravings, lower back ache and feeling more tired are common. So are mood changes: many people feel more irritable, teary or anxious in the days before bleeding starts. See signs your period is coming.
Lulu predicts your next period from your own history and learns how you usually feel in the days before it, so the date comes with a heads-up about the harder days too.
When to talk to a doctor
See a doctor if your period is more than a week late with a negative pregnancy test and it keeps happening, if periods stop for 3 months or more, if cycles are regularly under 21 or over 35 days, or if you have very heavy bleeding or bleeding between periods.
Frequently asked questions
How do I calculate my next period date?
Add your usual cycle length to the first day of your last period. A period that started on 1 March with a 29-day cycle points to 30 March.
How many days late is normal?
Up to about a week either way is common, especially if your cycles already vary. See how late can a period be.
Why did my period come early?
Usually because you ovulated earlier than usual. Stress, illness and perimenopause can all shorten a cycle. More in why is my period early.
Does day 1 start when I spot?
No. Day 1 is the first day of real flow that needs a pad, tampon, cup or period underwear.
Sources
This page is for information only and isn’t medical advice. If something worries you, please talk to a doctor.
Keep reading
Period calculator: when is my next period?Free period calculator: enter the first day of your last period and your cycle length to see your next 6 periods. Private, instant, nothing is stored.
How late is my period? Check in secondsHow late is my period? Enter your last period and cycle length to see exactly how many days late you are, whether that's normal, and what to do next.Why is my period late? 10 common reasonsWhy is my period late if you're not pregnant? Stress, late ovulation, weight change, PCOS, perimenopause and more, plus when a late period needs a doctor.How do you know your period is coming?Signs your period is coming: cramps, bloating, sore breasts, spots, cravings, tiredness and mood changes. When each one starts and how to read your own.
Irregular periods: what counts, common causes and what helpsIrregular periods explained: what counts as irregular, why cycles vary, common causes like PCOS, thyroid and perimenopause, and when to see a doctor.