Pregnancy Due Date Calculator

Estimate your due date and how far along you are, from your last period.

Your Dates

Your Estimate

Estimated Due Date

How far along
Trimester
Estimated conception

Frequently Asked Questions

The common method (Naegele\u2019s rule) adds 280 days (40 weeks) to the first day of your last period. We adjust for your cycle length if it differs from 28 days.
It is an estimate — only about 4% of babies arrive on the exact due date. A dating scan gives a more accurate figure.
No. Like every KwikSum tool, the calculation runs entirely in your browser and nothing is sent anywhere.

Working Out Your Due Date

Pregnancy is counted from the first day of your last menstrual period (LMP), not from conception, which is usually about two weeks later. A full-term pregnancy is around 40 weeks from the LMP.

Related calculators

Count the days with the date calculator or work out a future date with the age calculator. This tool is for general guidance, not medical advice.