maternity calculator hmrc - Aaron Graves, PhDude Replica

HMRC Statutory Maternity Pay (SMP) Calculator

Estimate your UK Statutory Maternity Pay using HMRC-style rules: first 6 weeks at 90% of average weekly earnings, then up to 33 weeks at the lower of 90% of earnings or the standard SMP rate.

Average weekly earnings before tax (£) Use your average gross weekly earnings in the relevant calculation period.

Lower Earnings Limit (LEL) (£/week) This changes by tax year. Update if needed.

Standard SMP rate (£/week) This usually updates each April. Check latest HMRC guidance.

Weeks to calculate (1 to 39)

Expected due date (optional)

Maternity leave/pay start date (optional)

I expect to have at least 26 weeks' continuous employment by the qualifying week.

How this maternity calculator works

This page is built for people searching for a maternity calculator HMRC style estimate. It focuses on Statutory Maternity Pay (SMP) in the UK and gives a quick planning figure based on the core formula employers and payroll systems use.

At a high level, SMP is paid for up to 39 weeks:

Weeks 1–6: 90% of your average weekly earnings (AWE)
Weeks 7–39: the lower of 90% of AWE or the standard weekly SMP rate

What you need before calculating

1) Average Weekly Earnings (AWE)

Your AWE is usually calculated from your gross pay in a specific period before your qualifying week. If your earnings vary, get the exact figure from payroll or HR for best accuracy.

2) Lower Earnings Limit (LEL)

To qualify for SMP, your average weekly earnings generally need to be at least the Lower Earnings Limit for National Insurance in the relevant year.

3) Continuous employment

Eligibility usually also depends on continuous employment with your employer through the qualifying week. This calculator includes a checkbox so you can quickly model likely eligibility.

Example calculation

If your AWE is £500:

90% of AWE = £450
Weeks 1–6 pay = £450/week
Weeks 7–39 pay = min(£450, standard rate) = standard rate (if standard rate is lower)

In other words, most people with moderate or high earnings will receive the standard SMP weekly rate after week 6, while lower earners may continue to receive 90% of AWE if that amount is lower than the standard rate.

HMRC maternity pay planning tips

Budget monthly: convert weekly SMP into a monthly plan to avoid cash-flow surprises.
Check enhanced employer schemes: some employers top up pay above statutory minimums.
Confirm dates early: due date and leave start date can affect timing and admin.
Review deductions: SMP is taxable and may include National Insurance impacts.

Frequently asked questions

Is this an official HMRC tool?

No. This is an educational calculator that mirrors common SMP rules. Always confirm final entitlement with your employer/payroll and the latest HMRC guidance.

What if I am not eligible for SMP?

You may still be able to claim Maternity Allowance depending on your employment and National Insurance history. If this tool flags you as potentially ineligible, check GOV.UK for next steps.

Can I calculate more than 39 weeks?

SMP itself is generally paid for a maximum of 39 weeks. You can still take up to 52 weeks of maternity leave in many cases, but pay beyond SMP limits may be unpaid unless your employer offers enhanced terms.

Important note

This calculator is for planning and educational purposes only. Rates and thresholds can change each tax year. For a final, legally accurate figure, use your payroll details and current HMRC rules.