Choose how to calculate — from your last period, the date of intercourse, an ultrasound result or the BPD measurement alone. The calculator works out your approximate week of pregnancy and shows which method would suit your case.
You will find this value in the scan report (abbreviated "BPD"). Enter the date of the scan — if it was done earlier, the calculator adds the days up to today. This method is more approximate than the others: BPD is a population range rather than a fixed value and varies somewhat between individuals. If you also know the date of your last period, it is worth comparing the results.
The result is approximate — the exact stage of pregnancy is established by an ultrasound at the clinic. The calculation runs in your browser; nothing is sent anywhere.
Weeks of pregnancy are counted from the first day of your last menstrual period (LMP), in line with WHO standards — not from the date of conception. By the time you find out you are pregnant, you are usually already 4–5 weeks along. If you cannot remember the exact date of your period, the calculator can also work from the approximate date of intercourse (adding the standard 14 days to ovulation), from a gestational age established earlier on a scan, or from the BPD measurement alone — useful when all you have to hand is a scan report without dates. Whichever method you use, the exact stage is always confirmed by an ultrasound at the clinic.
| Trimester | Weeks | Method |
|---|---|---|
| First trimester | 1–12 | Vacuum aspiration (from week 6) |
| Second trimester | 13–27 | Instrumental procedure (D&E) (up to week 22) |
| Third trimester | 28–40 | Procedure not available |
You can book a procedure at our clinic — usually within 3–5 days. See how to prepare.
The doctor chooses the method after the ultrasound. Read about vacuum aspiration and D&E.
The procedure is entirely legal in the Netherlands, with no consequences back home. Legal details.
We talk in confidence, without judgement — and we'll help you find a date.
