Use Me Calc
English (UK)

Pregnancy due date calculator

Find your due date, how many weeks pregnant you are and when your NHS antenatal appointments are.

Tabnext field ⌘Ksearch

Usually 28 days. A longer or shorter cycle moves the due date later or earlier.

Pick a date to see your due date, how far along you are, how many days are left, and when your next antenatal appointment is.

Everything runs in your browser. Nothing you enter is uploaded.

How to use

  1. Choose what to calculate from:
    • Last period: the first day of your last period. This is what most people use before their dating scan.
    • Conception: if you tracked ovulation and know the date.
    • IVF transfer: the date of your embryo transfer, and whether it was a day-3 or day-5 embryo.
    • Known due date: the date from your dating scan, to see how far along you are.
  2. Pick the date. For the last-period method, change the cycle length if yours isn’t 28 days.
  3. You get your due date, how many weeks and days pregnant you are today, your trimester, the days left and the date of your next antenatal appointment. Below that are the usual NHS appointments for a first baby, each with a date.

How it’s calculated

  • From your last period: due date = first day of last period + 280 days + (cycle length − 28) days
  • From conception: due date = conception date + 266 days
  • From an IVF transfer: due date = transfer date + 261 days (day-5 embryo) or + 263 days (day-3 embryo)
  • Weeks pregnant = today − (due date − 280 days), shown as weeks and days

For example, if your last period started on 1 May 2026 and your cycle is 28 days, your due date is 5 February 2027. On 13 October 2026 you would be 23 weeks and 4 days pregnant, in your second trimester, with 115 days to go. With a 32-day cycle the due date moves to 9 February 2027.

A day-5 IVF transfer on 12 June 2026 gives a due date of 28 February 2027; a day-3 transfer on the same day gives 2 March 2027.

NHS antenatal appointments

For a due date of 5 February 2027, the usual appointments for a first baby fall in these weeks:

Week Date What happens
By 10 10/07/2026 Booking appointment with your midwife
11–14 around 24/07/2026 Dating scan, and screening for Down’s, Edwards’ and Patau’s syndromes if you choose it
16 21/08/2026 Midwife appointment
18–21 around 18/09/2026 20-week screening scan
25 23/10/2026 Midwife appointment (first baby only)
28 13/11/2026 Blood tests, and anti-D if you’re rhesus negative
31 04/12/2026 Midwife appointment (first baby only)
34 25/12/2026 Midwife appointment
36 08/01/2027 Checking your baby’s position
38 22/01/2027 Midwife appointment
40 05/02/2027 Your due date
41 12/02/2027 Membrane sweep and induction discussed

If a date falls on a bank holiday, like the 34-week appointment here on Christmas Day, your midwife will book the nearest working day. If you’re at higher risk of gestational diabetes you’ll also be offered a glucose test between 24 and 28 weeks.

Reminder

This calculator estimates dates. It doesn’t replace your antenatal care. If anything feels wrong during your pregnancy, contact your midwife, GP or maternity unit, or call NHS 111.

FAQ

How is my due date worked out?

The usual method adds 280 days (40 weeks) to the first day of your last period. If your cycle is longer or shorter than 28 days, the date moves later or earlier by the difference. From a known conception date, the due date is 266 days (38 weeks) later. Pregnancy normally lasts between 37 and 42 weeks, so the due date is an estimate.

Will my dating scan change my due date?

It may. The dating scan between 11 and 14 weeks measures your baby and gives a more accurate idea of how far along you are than the date of your last period. If the two don't match, your midwife will usually go by the scan. Choose "Known due date" and enter the date from your scan to see your weeks and appointment dates.

How is the due date calculated after IVF?

From the transfer date and the embryo's age rather than your last period. The due date is 261 days after transferring a day-5 embryo (blastocyst), or 263 days after a day-3 embryo. Your fertility clinic will confirm the date.

What are the trimesters in the UK?

The NHS counts the first trimester up to week 12, the second trimester from week 13 to week 27, and the third trimester from week 28 until birth.

What happens if I go past my due date?

Only around 1 in 20 babies arrives on the due date. If you haven't gone into labour, your midwife will usually offer a membrane sweep after 39 weeks, and induction is offered if labour hasn't started naturally by 41 weeks.

How many antenatal appointments will I have?

On the NHS, at least 10 if this is your first baby, including 2 ultrasound scans, and at least 7 in later pregnancies. You'll see more of your midwife or a doctor if you need extra care.

Sources

Last updated：

Related tools