CCalcanova
👶
Converters & Dates

Pregnancy Due Date Calculator

Estimate your due date from your last period or conception date, and see how many weeks along you are today.

days

28 days is the standard; a longer cycle moves the date later

Estimated due date
Monday, March 8, 2027
How far along today
8 weeks 0 days
Current trimester
First trimester
Days remaining
224 days
Estimated conception date
Jun 15, 2026
2nd / 3rd trimester start
Aug 31, 2026 · Dec 7, 2026

About 20% of the way through a 40-week pregnancy.

This is an estimate based on Naegele's rule — a 40-week (280-day) pregnancy counted from the first day of your last period. Only about 1 in 20 babies arrive exactly on the due date, and most births happen in the two weeks either side. It is general information, not medical advice: an early dating scan from your healthcare provider is the authoritative due date.

Estimating a due date

This calculator uses Naegele's rule — a 40-week (280-day) gestation counted from the first day of your last menstrual period. Choose the conception date instead and the equivalent last period is taken as two weeks earlier, which is the same convention clinics use. It is an estimate for planning, not a medical assessment: only about 1 in 20 births occur exactly on the due date, and a dating scan from your healthcare provider is the authoritative answer.

Worked example

With a last period starting Monday 1 June 2026 and a typical 28-day cycle, conception is estimated around 15 June and the due date falls on Sunday 7 March 2027. The second trimester starts 13 weeks after the last period, on 31 August 2026, and the third starts at 27 weeks, on 7 December 2026.

What the numbers mean

"How far along" is completed weeks plus days of gestation today, written the way midwives write it — 12 weeks 3 days. Days remaining counts down to the estimated due date and goes past it if that date has already passed, which is normal and happens to a large share of first pregnancies. None of this replaces antenatal care: use it to plan leave, appointments, and travel, and confirm every date with your provider.

Frequently asked questions

+How accurate is a due date?

Treat it as the middle of a range, not an appointment. Only about 1 in 20 births happen on the due date itself; most arrive in the two weeks either side, and a pregnancy is considered full term from 39 weeks. An early ultrasound dating scan is more accurate than any date-based estimate, and if it disagrees with your dates by more than about a week your provider will usually re-date the pregnancy from the scan.

+Why does the count start before conception?

Pregnancy is conventionally dated from the first day of your last period, roughly two weeks before ovulation and conception. That means you are counted as "2 weeks pregnant" at the moment of conception. It is done this way because the date of a period is far easier to remember than the date of ovulation.

+What if my cycle isn't 28 days?

Naegele's rule assumes ovulation on day 14 of a 28-day cycle. If your cycles are consistently longer or shorter, ovulation shifts with them, so the calculator moves the estimate by the difference — a 32-day cycle pushes the due date about 4 days later. Enter your usual cycle length in the field provided.

+When do the trimesters start?

The first trimester covers weeks 0 to 12, the second begins at 13 weeks, and the third begins at 27 weeks. Boundaries vary slightly between sources, so a chart from your clinic may differ by a week.

More converters & dates tools

📐Unit Converter⏱️Time Converter🎂Age