Pregnancy Due Date Calculator
Estimate a pregnancy due date from the last period or conception date.
An estimated arrival window
A due date estimates when a baby is likely to arrive, calculated from the first day of the last menstrual period or a known conception date, based on a typical pregnancy length. This gives that estimated date as a reference point for a pregnancy.
Enter the relevant date to estimate a due date.
An estimate, and babies keep their own time
A due date is genuinely an estimate, not a deadline — only a small share of babies arrive exactly on it, and a normal, healthy birth can happen across a window of a couple of weeks either side. The standard calculation assumes a typical cycle length and pregnancy duration, so it can be off for individual variation, which is why a healthcare provider often adjusts the date using an early ultrasound. It is a useful anchor for planning and for tracking a pregnancy, understood as an approximate window rather than a fixed day. This is general information, not medical advice; pregnancy care and dating are matters for your healthcare provider.
Frequently asked questions
How accurate is a due date?
It is an estimate — only a small share of babies arrive exactly on it, and healthy births occur across a window of a couple of weeks either side.
How is it calculated?
Usually from the first day of the last period, assuming a typical cycle and pregnancy length, or from a known conception date. A provider may adjust it by ultrasound.
Is this medical advice?
No — it is general information. Pregnancy care and accurate dating are matters for your healthcare provider.