Maternity leave calculator
Work out the key dates for your maternity leave from your due date: when it can start, when to tell your employer and when it ends.
Rules from GOV.UK, checked 13 November 2026.
Result
Enter your due date to see your dates.
When maternity leave can start
Usually, the earliest you can start your leave is 11 weeks before the expected week of childbirth. That week runs from Sunday to Saturday, so it starts on the Sunday on or before your due date. Leave also starts the day after the birth if the baby is early, or automatically if you are off with a pregnancy-related illness in the 4 weeks before the week your baby is due.
Telling your employer
At least 15 weeks before your due date, tell your employer when the baby is due and when you want your leave to start. For Statutory Maternity Pay, give at least 28 days' notice of when you want it to start, with proof of your pregnancy. GOV.UK explains how to claim.
How long it lasts
Statutory Maternity Leave is 52 weeks: 26 weeks of Ordinary Maternity Leave and 26 of Additional. You do not have to take it all, but you must take 2 weeks after the birth, or 4 if you work in a factory. Statutory Maternity Pay lasts up to 39 weeks: the maternity pay calculator works out how much.