Pregnancy Due Date Calculator
Calculate your due date from the last menstrual period, conception date, or IVF transfer date — with current week and trimester milestones. Free, private.
The estimated due date is 40 weeks from the first day of your last menstrual period (Naegele's rule) — or 38 weeks from conception, which IVF dates know exactly. This calculator handles all three inputs and shows where you are right now: current week, trimester, and the milestones ahead.
It runs entirely in your browser — dates you enter are health information that never leaves your device, and no account or email is needed.
100% in-browser · no upload · no signup · nothing you paste or drop here leaves your device
Pregnancy Due Date Calculator
Estimate your due date with Naegele\u2019s rule, plus gestational age and trimester — 100% private.
Naegele's rule gives an estimated due date. Only ~4% of babies arrive exactly on that date; a full-term birth ranges from 37 to 42 weeks. Your healthcare provider will confirm with ultrasound.
The 40‑week journey, day by day
The estimated due date is 280 days (40 weeks) from the first day of your last menstrual period. Conception typically happens about two weeks later — around ovulation.
For a 28-day cycle. If your cycle differs, an adjustment of +(cycle − 28) days is applied — the calculator does this automatically.
Last menstrual period: March 10, 2026, average 28-day cycle.
- Add 280 days:March 10 + 280 days = December 15, 2026
- Cycle adjustment:Cycle 28 → none needed (28 − 28 = 0)
- Conception:≈ March 24 — about two weeks after the LMP
- Due date (EDD):December 15, 2026
About this pregnancy due date calculator
This page covers calculate my due date, how many weeks pregnant calculator, due date from conception date, ivf due date calculator — all the same underlying task as pregnancy due date calculator. The tool above is FreeToolHub's due date calculator embedded in full: every feature works right here, and nothing you process is uploaded to any server.
Frequently asked questions
How accurate is a pregnancy due date calculator?
It produces the same estimate an OB would at the first visit — and only about 4% of babies arrive exactly on it. Roughly 80% arrive within the ±10-day window around the due date. The 20-week ultrasound can shift the estimate by days; treat the calculated date as the center of a window, not a deadline.
Should I use LMP or conception date?
LMP is the clinical standard because it is usually known more precisely than conception — ovulation happens about two weeks after LMP on average but varies by person. If you know the conception or IVF transfer date exactly, use that input; the calculator adjusts to the clinically correct gestational age either way.