Pregnancy Due Date Calculator: From Last Period, Conception or IVF
Enter the first day of your last period, your conception date or your IVF transfer date to see your estimated due date and a week-by-week calendar.
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Due date
Wed, 11 Aug 2027
- Today you are
- 0 weeks
- 2nd trimester starts
- Wed, 10 Feb 2027
- 3rd trimester starts
- Wed, 19 May 2027
- Full term from (37 weeks)
- Wed, 21 Jul 2027
An estimate for general information, not medical advice. Dates can differ by a week or two; confirm with your doctor or ANM.
Most babies arrive between 37 and 42 weeks. Your doctor may update the date after an early scan.
Week-by-week calendar
| Week | Starts on | Trimester |
|---|---|---|
| 1 | Wed, 4 Nov 2026 | 1 |
| 2 | Wed, 11 Nov 2026 | 1 |
| 3 | Wed, 18 Nov 2026 | 1 |
| 4 | Wed, 25 Nov 2026 | 1 |
| 5 | Wed, 2 Dec 2026 | 1 |
| 6 | Wed, 9 Dec 2026 | 1 |
| 7 | Wed, 16 Dec 2026 | 1 |
| 8 | Wed, 23 Dec 2026 | 1 |
| 9 | Wed, 30 Dec 2026 | 1 |
| 10 | Wed, 6 Jan 2027 | 1 |
| 11 | Wed, 13 Jan 2027 | 1 |
| 12 | Wed, 20 Jan 2027 | 1 |
| 13 | Wed, 27 Jan 2027 | 1 |
| 14 | Wed, 3 Feb 2027 | 1 |
| 15 | Wed, 10 Feb 2027 | 2 |
| 16 | Wed, 17 Feb 2027 | 2 |
| 17 | Wed, 24 Feb 2027 | 2 |
| 18 | Wed, 3 Mar 2027 | 2 |
| 19 | Wed, 10 Mar 2027 | 2 |
| 20 | Wed, 17 Mar 2027 | 2 |
| 21 | Wed, 24 Mar 2027 | 2 |
| 22 | Wed, 31 Mar 2027 | 2 |
| 23 | Wed, 7 Apr 2027 | 2 |
| 24 | Wed, 14 Apr 2027 | 2 |
| 25 | Wed, 21 Apr 2027 | 2 |
| 26 | Wed, 28 Apr 2027 | 2 |
| 27 | Wed, 5 May 2027 | 2 |
| 28 | Wed, 12 May 2027 | 2 |
| 29 | Wed, 19 May 2027 | 3 |
| 30 | Wed, 26 May 2027 | 3 |
| 31 | Wed, 2 Jun 2027 | 3 |
| 32 | Wed, 9 Jun 2027 | 3 |
| 33 | Wed, 16 Jun 2027 | 3 |
| 34 | Wed, 23 Jun 2027 | 3 |
| 35 | Wed, 30 Jun 2027 | 3 |
| 36 | Wed, 7 Jul 2027 | 3 |
| 37 | Wed, 14 Jul 2027 | 3 |
| 38 | Wed, 21 Jul 2027 | 3 |
| 39 | Wed, 28 Jul 2027 | 3 |
| 40 | Wed, 4 Aug 2027 | 3 |
| 41 | Wed, 11 Aug 2027 | 3 |
| 42 | Wed, 18 Aug 2027 | 3 |
How to use
- Choose how to calculate: last period, conception or IVF transfer.
- Enter the date (and cycle length or embryo age if asked).
- See your estimated due date, trimester dates and the week calendar.
Good to know
From the last period, the due date is 280 days (40 weeks) after its first day — Naegele's rule — moved later or earlier by the number of days your cycle is longer or shorter than 28. From conception it is 266 days later. After IVF it is 261 days after a day-5 (blastocyst) transfer or 263 days after a day-3 transfer.
Pregnancy weeks are counted from the last period, not from conception, so at conception you are already about 2 weeks pregnant. The 2nd trimester starts at 14 weeks and the 3rd at 28 weeks (ACOG). Full term is from 37 weeks.
Only about 1 in 20 babies arrive on the due date; most come within two weeks either side. An early ultrasound (before about 14 weeks) is the most accurate way to date a pregnancy, and your doctor may change the due date after it. Please book your antenatal check-ups — in India, registration at your nearest health centre also gives access to free schemes like PMSMA check-ups.
Questions
How is the due date calculated?
Add 280 days (40 weeks) to the first day of your last period, adjusting for cycles longer or shorter than 28 days. That is the same as adding 9 months and 7 days.
My cycle is 35 days. Does that change the due date?
Yes. A longer cycle usually means later ovulation, so the due date moves 7 days later than for a 28-day cycle.
How accurate is the due date?
It is an estimate. Most babies are born between 37 and 42 weeks. An early dating scan is more accurate than period dates.
How is the IVF due date worked out?
For a day-5 embryo transfer, add 261 days to the transfer date; for a day-3 transfer, add 263 days.
Is my data saved?
No. Dates are calculated on your device and never sent anywhere.