mat leave calculator uk

How maternity leave works in the UK

In the UK, eligible employees can take up to 52 weeks of maternity leave. This is usually split into:

• Ordinary Maternity Leave (first 26 weeks)
• Additional Maternity Leave (next 26 weeks)

Not all leave is paid. Under statutory rules, up to 39 weeks may be paid through SMP if eligibility conditions are met, while the remaining weeks are generally unpaid unless your employer provides enhanced maternity pay.

How SMP is normally calculated

Standard calculation

For many employees, SMP follows this pattern:

• First 6 weeks: 90% of average weekly earnings
• Next 33 weeks: the lower of 90% of average weekly earnings or the statutory weekly rate

Your average weekly earnings are usually based on a defined earnings period before your qualifying week. Payroll teams handle this precisely, but this calculator gives a strong planning estimate.

Eligibility basics

To qualify for SMP, you generally need to:

• Have been employed continuously by the same employer for at least 26 weeks by the qualifying week
• Earn at least the Lower Earnings Limit on average
• Provide the required notice and evidence (such as MATB1)

If you do not qualify for SMP, you may still be entitled to Maternity Allowance.

How to use this mat leave calculator uk tool

1. Enter your average weekly earnings before tax.
2. Select your maternity leave start date.
3. Choose total leave weeks (up to 52).
4. Set paid weeks and high-rate weeks (defaults are 39 and 6).
5. Check the statutory rate and LEL values for the relevant year.
6. Click calculate for a full breakdown.

The result includes estimated total paid amount, unpaid weeks, and expected return date if you take the full selected leave period.

Example scenario

Suppose your average weekly earnings are £600, you take 52 weeks leave, and SMP settings stay at 39 paid weeks with 6 high-rate weeks:

• Weeks 1–6: 90% of £600 = £540/week
• Weeks 7–39: lower of £540 or statutory weekly rate (statutory rate applies)
• Weeks 40–52: unpaid

This helps you estimate your total maternity income and identify where savings might be needed during unpaid weeks.

Budget planning tips for maternity leave

• Create a month-by-month cash-flow forecast before leave begins.
• Separate fixed costs (rent, mortgage, childcare prep) from variable costs.
• Build an emergency buffer for unexpected baby and household expenses.
• Check whether your employer offers enhanced maternity package terms.
• Review household benefits and tax credit/Universal Credit eligibility.
• Plan your return-to-work timing and potential childcare start date early.

SMP vs enhanced maternity pay

Some employers top up maternity pay above the statutory minimum. That policy can significantly change your total income, especially in weeks 7–39 or even beyond 39 weeks in some schemes. Always compare this calculator's estimate against your contract, staff handbook, or HR policy documents.

Frequently asked questions

Do I get paid for the full 52 weeks?

Usually no. Statutory maternity leave can be 52 weeks, but statutory pay is generally up to 39 weeks.

What if my average weekly earnings are low?

If average weekly earnings are below the Lower Earnings Limit, SMP may not apply. You may still be eligible for Maternity Allowance depending on your work history.

Can this calculator replace payroll advice?

No. It is an estimate tool for planning. Final entitlement and exact figures should come from your employer/payroll and official GOV.UK guidance.