Free Pregnancy Date Calculators: IVF, Conception, LMP & Ultrasound
Pick a method and get your estimated due date in seconds. IVF, conception, LMP, ultrasound, twins, cycle, luteal phase, and how-far-along — all private, in your browser.
IVF, LMP, conception & more — all worked out on your deviceEstimates only — not medical advice. Confirm all dates and milestones with your doctor or midwife. Read our full disclaimer.
How this due date is calculated
Pick your embryo transfer type, then enter the transfer (or thaw) date. The due date is the transfer date plus the standard offset for that embryo stage: Day-3 +263, Day-5 +261, Day-6 +260, frozen/donor/surrogate +261 days.
This site gathers several ways to estimate a due date — by last period, conception, IVF transfer, ultrasound, twins, adjusted cycle length, or luteal phase — plus tools to work backwards ("how far along") and to track a week-by-week timeline. Each method has its own page with its own explanation, because the underlying math differs: LMP adds 280 days while conception adds 266, and an IVF or ultrasound date replaces the period entirely. Pick the method that matches how you know your dates, and remember that an early ultrasound from your provider is the most accurate way to set an official due date.
What to expect
BumpDate is a small set of free calculators for pregnancy date math. Instead of one giant form, each method has its own page so you can go straight to the one you need: due date by last period (LMP), by conception date, by IVF embryo transfer, by ultrasound, for twins and multiples, adjusted for cycle length or luteal phase, plus "how far along am I" and a week-by-week view.
Every tool runs entirely in your browser. The dates you type are processed on your own device and are never uploaded to a server, so nothing leaves your computer. There are no accounts to create and no tracking scripts that follow you around the web.
The methods are the standard ones used in obstetrics. Naegele's rule puts the due date 280 days (40 weeks) after the first day of your last period. IVF due dates add a fixed number of days to the embryo transfer date, depending on the embryo stage. Ultrasound dating works backwards from the baby's measured gestational age. None of these are unique to BumpDate — they are the same formulas a due-date wheel or your clinic's software would use.
A due date is an estimate, not a deadline. Only a small fraction of babies arrive exactly on the date, and your provider may move it after an early ultrasound, which is the most accurate way to date a pregnancy. Use these calculators for planning — figuring out roughly when to schedule appointments, announce, or pack a hospital bag — and let your care team confirm the official date.
Pick a method from the list below to get started. If you are doing IVF, the IVF transfer calculator at the top is the fastest place to begin.
Important note
These calculators use standard formulas — Naegele's rule (LMP + 280 days) and common IVF conventions (transfer date + 260–263 days). They give estimates for planning only. They are not a substitute for prenatal care, and only your provider can confirm your due date and track your baby's development. See the disclaimer for details.
FAQ
Which due date method should I use?
Use the method that matches how you know your dates: LMP if you know your last period, conception if you tracked ovulation, IVF if you had a transfer, or ultrasound if you have a scan date with a measured age. Each has its own page with a dedicated calculator and its own explanation.
Why are there so many due date calculators?
Because the due date is computed differently depending on the starting point. LMP adds 280 days, conception adds 266, an IVF transfer adds 260–263 from the transfer day, and an ultrasound works backwards from a measured age. The right one depends on what you actually know.
Is my data private?
Yes. Every calculator on this site runs entirely in your browser. The dates you enter are never uploaded to a server and no account is required.