Due Date Calculator

How the calculation works

Choose how you want to calculate. From the last period, the due date is 280 days later (adjusted for cycle length). From conception, it is 266 days later. The results also show your current week and the key dates of each trimester.

Formula used

Due date = last period + 280 days, or conception date + 266 days

Example

A last period starting 21 August 2026 gives a due date of 28 May 2027.