Last reviewed: May 2026
Key facts:- Statutory Maternity Pay is paid for up to 39 weeks, with the first six weeks at 90 per cent of average weekly earnings and the remaining 33 weeks at the standard SMP rate.
- The 2025/26 standard SMP rate was 184.03 pounds a week or 90 per cent of average weekly earnings if that is lower; the 2026/27 rate is uprated by September 2025 CPI.
- Eligibility requires 26 weeks of continuous employment by the qualifying week and average weekly earnings at or above the Lower Earnings Limit.
UK Employment Rights Hub › Maternity Pay Calculator Guide
Statutory Maternity Pay is the legal minimum that an eligible pregnant employee receives during maternity leave. Many employers pay enhanced contractual maternity pay on top, but SMP is the floor. This guide explains how to calculate SMP step by step, the difference between the first six weeks and the remaining 33 weeks, and how to use the official gov.uk maternity pay calculator to confirm the figures.
How SMP Works
Statutory Maternity Pay is paid by the employer through the payroll. PAYE tax and Class 1 National Insurance contributions are deducted in the usual way. Employers can normally recover most of SMP from HMRC under the Statutory Maternity Pay Recovery Scheme; small employers can claim 103 per cent.
SMP is payable for up to 39 weeks. Maternity Leave itself can last up to 52 weeks - the additional 13 weeks of leave are unpaid. The employee can return to work earlier than 52 weeks, but must give the employer at least eight weeks notice of the proposed return date.
SMP rates are uprated each April in line with September CPI. The 2025/26 standard rate was 184.03 pounds a week. The 2026/27 rate is uprated by the September 2025 CPI figure announced in the Autumn Statement.
The Qualifying Week and Average Earnings
The qualifying week is the 15th week before the expected week of childbirth. The employee must have been continuously employed by the same employer for at least 26 weeks by the end of the qualifying week, and must have average weekly earnings at or above the Lower Earnings Limit in the eight weeks ending with the qualifying week.
Average weekly earnings are calculated by taking the gross pay in the eight weeks before the qualifying week and dividing by eight. For monthly paid employees, the calculation uses the last two normal payslips before the qualifying week, divided by two and then multiplied by 12 over 52.
Pay rises that take effect between the start of the average earnings reference period and the start of maternity leave must be included retrospectively, even if the original SMP rate was calculated without them. This is known as the Alabaster rule, following the case Alabaster v Woolwich Building Society.
Calculating the First Six Weeks
The first six weeks of SMP are paid at 90 per cent of average weekly earnings. There is no upper cap on this 90 per cent rate. A higher-earning employee can therefore receive substantially more in the first six weeks than in the remaining 33 weeks.
Example: if average weekly earnings are 500 pounds, the first six weeks SMP is 450 pounds a week. If average weekly earnings are 1,000 pounds, the first six weeks SMP is 900 pounds a week. The figure is gross; tax and NI are deducted in the normal way.
Employees with contractual maternity pay enhancements may receive more than SMP during the first six weeks. The contractual scheme tops up the SMP rather than replacing it. The terms of the enhanced scheme are set out in the employer maternity policy.
Calculating Weeks Seven to 39
From week seven onwards, SMP is paid at either the standard SMP rate or 90 per cent of average weekly earnings, whichever is lower. For most employees, the standard rate is lower and applies for the remaining 33 weeks.
Example: if average weekly earnings are 500 pounds, the standard rate (2025/26: 184.03 pounds) is lower than 90 per cent of 500 (450 pounds), so the standard rate applies. If average weekly earnings are 150 pounds, 90 per cent (135 pounds) is lower than the standard rate, so the 90 per cent rate continues.
The standard SMP rate is the same regardless of the employee total earnings. Enhanced contractual schemes often top up to a higher amount, sometimes to full pay for a defined number of weeks. The contractual top-up is on top of SMP, not instead of it.
Using the Gov.uk Maternity Pay Calculator
HMRC provides a maternity pay calculator on gov.uk. The calculator asks for the expected date of childbirth, the date the employee plans to start maternity leave, and the gross pay over the relevant reference period. It returns a week-by-week breakdown of SMP entitlement.
The calculator is the most accurate route for individual employees because it applies the current SMP rate and the Alabaster rule automatically. Employers payroll software should also calculate SMP correctly; the calculator provides a useful cross-check.
Where the employee does not qualify for SMP - because of insufficient continuous employment, low average earnings, or self-employment - the calculator points to Maternity Allowance, which is paid by DWP instead. Maternity Allowance has different qualifying conditions and is claimed on form MA1.
Common SMP Calculation Pitfalls
Recent pay rise not applied. The Alabaster rule requires retrospective application of a pay rise that takes effect between the start of the reference period and the end of maternity leave. Employers sometimes overlook this. A small back payment is usually made when the issue is raised.
Bonus payments missed from earnings calculation. Bonuses, commission and overtime that fall within the eight-week reference period should be included in the average weekly earnings calculation. They are sometimes excluded by payroll systems that only capture base salary, leading to under-calculated SMP.
Salary sacrifice for pension or childcare. Salary sacrifice arrangements reduce the gross salary for average weekly earnings calculation purposes. This can push lower-paid workers below the Lower Earnings Limit and out of SMP eligibility. Some employers pause salary sacrifice during the reference period to protect SMP.
Confusing SMP with Maternity Allowance. Workers who do not qualify for SMP because of insufficient continuous employment should claim Maternity Allowance from DWP instead. The two schemes have similar rates but different qualifying conditions and are administered by different bodies.
Where to Get Free Independent Help
Acas (the Advisory, Conciliation and Arbitration Service) is the statutory body that provides free guidance to workers and employers on workplace issues including maternity pay calculator. The Acas helpline is the first port of call for many employment law questions. Acas also runs early conciliation before Employment Tribunal claims.
Citizens Advice and law centres provide free initial advice on maternity pay calculator. Some law centres have specialist employment law advisers and can represent claimants at Employment Tribunal hearings free of charge. The Law Centres Network website at lawcentres.org.uk lists centres by location.
Trade unions provide free legal advice and representation to members on maternity pay calculator. Even where the worker is not currently a union member, joining a union before issues arise gives access to professional advice if problems develop later. The TUC website at tuc.org.uk identifies relevant unions.
The Employment Tribunal handles workplace disputes that cannot be resolved through Acas. The tribunal is a no-cost jurisdiction (no fees to issue claims at the time of writing) and is designed to be accessible to litigants in person. The gov.uk employment tribunal pages explain the process.
For specific protected groups, dedicated organisations provide tailored support. The Equality Advisory Support Service helps with discrimination claims under the Equality Act 2010. Maternity Action specialises in pregnancy and maternity rights at work. Working Families is a charity supporting families with workplace flexibility issues.
Where the issue involves workplace health and safety, the Health and Safety Executive (HSE) is the enforcement body. HSE accepts reports from workers concerned about unsafe practices and can investigate. Reports are confidential to the extent practicable. The HSE website at hse.gov.uk explains how to raise a concern.
Putting It All Together
The rules above set out the legal framework, the practical steps and the support routes available. Where the situation is straightforward, the gov.uk pages and the official tools should be enough to act on. Where the situation is more complex, the free advice services listed in the previous section can usually clarify the position and identify the right next step. Many issues that look intractable at first turn out to be resolvable once the right service is engaged.
Keeping written records of communications and decisions throughout is good practice. Where a decision needs to be challenged later - through an internal complaint, an ombudsman, a tribunal or a court - the quality of the contemporaneous record often decides the outcome. Dates, names, reference numbers and copies of correspondence are the building blocks of any later dispute. The gov.uk advice pages and the relevant ombudsman or tribunal websites all set out the evidence they consider when reviewing decisions, and gathering that evidence from the start is one of the most effective protections available.
Frequently Asked Questions
How long is Statutory Maternity Pay?
Up to 39 weeks. The first six weeks are at 90 per cent of average earnings, the remaining 33 weeks at the standard SMP rate or 90 per cent of earnings, whichever is lower.
Do I qualify if I just started a new job?
Not for SMP. SMP requires 26 weeks of continuous employment by the qualifying week. Workers who do not qualify for SMP may instead claim Maternity Allowance from DWP.
How does the Alabaster rule work?
Pay rises during or shortly before maternity leave must be applied retrospectively to recalculate the average weekly earnings used for SMP. This usually results in a small SMP top-up payment.
Is SMP taxable?
Yes. SMP is taxable income and subject to PAYE deduction in the normal way. National Insurance contributions are also deducted from SMP. Employer pension contributions usually continue at the rate based on contractual salary, not on SMP.
Can I take maternity leave but not get SMP?
Yes. Statutory Maternity Leave is a right for all employees regardless of length of service. SMP requires 26 weeks continuous employment. Workers who qualify for leave but not SMP may claim Maternity Allowance from DWP.
When does SMP start?
SMP can start any time from 11 weeks before the expected week of childbirth, but must start by the day after the baby is born. Most employees choose to start SMP when their maternity leave begins.
Can I get SMP from more than one employer?
Yes. Each employer who meets the SMP eligibility rules pays SMP separately, based on the earnings with that employer. A worker with two qualifying jobs can receive SMP from both.
What is a Keeping in Touch (KIT) day?
A day worked during maternity leave by agreement with the employer. Up to 10 KIT days are allowed without losing SMP. The pay for KIT days is on top of SMP and is negotiated with the employer.
Does taking KIT days extend my maternity leave?
No. KIT days do not extend the leave. The leave end date is fixed at 52 weeks from the start, with the worker returning on that date regardless of KIT days taken.
Does my employer have to pay SMP?
Yes. Employers are required to pay SMP to eligible employees. The employer recovers most of the SMP from HMRC under the SMP Recovery Scheme.
How We Verified This
Information is taken from the Social Security Contributions and Benefits Act 1992, the Statutory Maternity Pay (General) Regulations 1986 on legislation.gov.uk, the gov.uk Statutory Maternity Pay pages, the HMRC SMP employer guidance, and the Alabaster v Woolwich Building Society case law on pay rises and average earnings.