When can maternity leave start in the UK?

Usually, the earliest Statutory Maternity Leave can start is 11 weeks before the expected week of childbirth.

When do I need to tell my employer I am pregnant?

GOV.UK says employees should tell their employer at least 15 weeks before the beginning of the week the baby is due.

Is this maternity leave calculator legal advice?

No. It is a planning tool only. Check GOV.UK and your employer policy for your exact entitlement and notice requirements.

DueDate.Baby

Maternity Leave Calculator UK

Last reviewed: July 2026Reviewed against cited UK guidance

Enter your due date to estimate useful UK maternity leave planning dates, including employer notice timing and the earliest usual leave start.

This page is for planning only and is not legal or employment advice. Check GOV.UK and your employer policy before making decisions.

Maternity leave date calculator

Enter your due date to estimate key UK maternity leave planning dates.

How the dates are estimated

UK maternity leave rules are based on the expected week of childbirth. This calculator uses the Sunday at the start of the week your baby is due, then estimates common planning dates from that week.

Key UK maternity leave reminders

Statutory Maternity Leave is up to 52 weeks.
The earliest usual start date is 11 weeks before the expected week of childbirth.
You normally need to tell your employer at least 15 weeks before the beginning of the week your baby is due.
For Statutory Maternity Pay, you usually need to give at least 28 days' notice of when you want pay to start.
Your doctor or midwife can give you a MATB1 certificate no more than 20 weeks before your due date.

Related pregnancy planning tools

Sources and further reading

Checked for UK maternity leave planning guidance in July 2026.

How we review content

We prioritise official NHS and GOV.UK guidance, then relevant professional-body information where needed.

Source links are checked on the review date shown above. Your midwife, GP, maternity team, fertility clinic, or employer can give advice that is more specific to your circumstances.