Last reviewed: May 2026
Key facts:- Statutory Maternity Pay runs for 39 weeks: first 6 weeks at 90 per cent of average weekly earnings, then 33 weeks at the standard SMP rate or 90 per cent if lower.
- Average weekly earnings are calculated over the eight weeks ending with the qualifying week, which is the 15th week before the expected date of birth.
- The official gov.uk maternity calculator returns a week-by-week breakdown applied to your own dates and earnings.
UK Employment Rights Hub › Maternity Pay Calculator Uk 2026
Working out maternity pay accurately matters - it affects family income for nearly a year and can decide when leave is taken and when work resumes. The gov.uk maternity and paternity calculator is the authoritative tool for individual calculations. This upgraded guide explains the calculation step by step so the calculator output can be checked, including the 90 per cent first six weeks, the standard SMP rate, and how the Alabaster rule on pay rises feeds in.
Step One - Confirm Eligibility
SMP eligibility has three tests. First, the employee must have been continuously employed by the same employer for at least 26 weeks ending with the qualifying week. The qualifying week is the 15th week before the expected week of childbirth.
Second, average weekly earnings in the eight weeks ending with the qualifying week must be at or above the Lower Earnings Limit for that tax year. The 2025/26 LEL was 125 pounds a week. The 2026/27 figure is set alongside the National Insurance contribution thresholds.
Third, the employee must give the employer notice of the planned start of maternity leave at least 28 days before that start date, together with evidence of the pregnancy (a MATB1 certificate from a midwife or GP).
Step Two - Calculate Average Weekly Earnings
Average weekly earnings are the gross pay in the eight weeks ending with the qualifying week, divided by eight. For weekly paid employees, the calculation uses the actual gross pay from each of those eight weeks.
For monthly paid employees, HMRC uses a slightly different method. The calculation takes the last two monthly payslips received before the qualifying week, sums them, and divides by two to give an average monthly pay. That figure is then multiplied by 12 and divided by 52 to give a weekly equivalent.
Bonuses, overtime and commission that fall within the reference period count toward average weekly earnings. So do payments in lieu of notice if they fall within the period. Pay rises that take effect during or shortly after the period must be applied retrospectively under the Alabaster rule.
Step Three - First Six Weeks at 90 Per Cent
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 receives substantially more in the first six weeks than in the remaining 33 weeks.
Example A: average weekly earnings 400 pounds. First six weeks SMP = 360 pounds per week. Total for the first six weeks = 2,160 pounds gross.
Example B: average weekly earnings 800 pounds. First six weeks SMP = 720 pounds per week. Total for the first six weeks = 4,320 pounds gross. PAYE tax and NI are deducted in the normal way.
Step Four - Weeks 7 to 39 at the Standard Rate
From week seven onwards, SMP is the lower of the standard SMP rate or 90 per cent of average weekly earnings. The standard rate is 184.03 pounds a week for 2025/26 (the 2026/27 figure is uprated by September 2025 CPI).
For most employees, the standard rate is lower than 90 per cent of their average weekly earnings, so the standard rate applies for the remaining 33 weeks. Total for weeks 7 to 39 at the standard rate = 33 weeks times 184.03 = 6,072.99 pounds gross for 2025/26.
For lower-earning employees, where 90 per cent of weekly earnings is below the standard rate, the 90 per cent calculation continues. Example: average weekly earnings 150 pounds. Standard rate is 184.03. The lower of the two is 135 pounds (90 per cent of 150), so weeks 7 to 39 = 33 times 135 = 4,455 pounds gross.
Step Five - Adjusting for Pay Rises and Enhanced Schemes
If the employee receives a pay rise between the start of the average earnings reference period and the end of maternity leave, the SMP must be recalculated as if the pay rise had been in effect throughout the reference period. This is the Alabaster rule. The employer usually pays a small top-up after the pay rise takes effect.
Enhanced contractual maternity pay schemes are common in larger employers. A typical scheme might pay full salary for the first 13 weeks, then 50 per cent for a further 13 weeks, then the standard SMP rate for the remaining 13 weeks. The enhanced amounts are paid through payroll alongside SMP.
Keeping in Touch (KIT) days allow the employee to work up to 10 days during maternity leave without losing SMP. KIT day pay is on top of SMP. The terms are negotiated with the employer before each KIT day.
Worked Examples with Different Pay Levels
Example A: Average earnings 400 pounds per week. First six weeks at 90 per cent = 360 pounds per week, total 2,160 pounds gross. Weeks 7 to 39 at the lower of 184.03 pounds or 90 per cent of 400 (360). Standard rate applies, so weeks 7 to 39 = 33 times 184.03 = 6,072.99 pounds. Grand total = 8,232.99 pounds gross over 39 weeks.
Example B: Average earnings 200 pounds per week. First six weeks at 90 per cent = 180 pounds per week, total 1,080 pounds. Weeks 7 to 39 at the lower of 184.03 or 90 per cent of 200 (180). The 90 per cent figure (180) is lower, so weeks 7 to 39 = 33 times 180 = 5,940 pounds. Grand total = 7,020 pounds.
Example C: Average earnings 800 pounds per week. First six weeks at 90 per cent = 720 pounds per week, total 4,320 pounds. Weeks 7 to 39 at the lower of 184.03 or 720. Standard rate is much lower, so weeks 7 to 39 = 33 times 184.03 = 6,072.99 pounds. Grand total = 10,392.99 pounds gross.
Tax and NI are deducted at the employee marginal rate. Employer pension contributions usually continue at the rate based on contractual salary, not on SMP. Enhanced contractual maternity pay schemes pay on top of SMP and are taxable in the normal way.
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 is SMP for the first six weeks calculated?
90 per cent of average weekly earnings. There is no cap. Higher earners receive more. The calculation is gross; tax and NI are deducted normally.
Why does the calculator show different amounts later in the leave?
After the first six weeks, SMP drops to the lower of the standard SMP rate or 90 per cent of average earnings. For most employees the standard rate applies, which is much lower than the first six weeks.
What is the Alabaster rule?
A pay rise during or shortly after the average earnings reference period must be applied retrospectively to SMP. The employer pays a top-up so the SMP reflects the post-rise earnings.
Can I work during maternity leave?
Yes. Up to 10 Keeping in Touch days are allowed without losing SMP. Working more than 10 days ends the SMP for the rest of the leave.
What if my employer pays enhanced maternity pay?
Enhanced pay is paid alongside SMP and on top of it. The contractual scheme tops up the SMP rather than replacing it. The terms of the enhanced scheme are in the employer maternity policy.
Where can I find the official calculator?
The gov.uk maternity and paternity calculator returns a week-by-week breakdown for individual dates and earnings. It is the authoritative tool and is updated with the current SMP rate each April.
What happens to my SMP if I start a new job during maternity leave?
SMP continues as long as the original employer pays it. Starting a new job during the SMP period does not stop the SMP, but the employee must tell the new employer about ongoing SMP from a previous employer for the new employer to handle PAYE correctly.
Can SMP be paid in a lump sum?
No. SMP is paid weekly through payroll, like normal salary. Lump sum payment is not permitted under the SMP regulations.
What about workplace pension contributions during SMP?
Most employers continue pension contributions at the pre-leave rate even though SMP is lower than normal pay. This is required by the Maternity and Parental Leave Regulations 1999 for occupational pension schemes.
How accurate is the gov.uk SMP calculator?
The calculator is the official tool and is updated each April with the current rates. It applies the Alabaster rule automatically. The output is reliable for typical employment arrangements.
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 case Alabaster v Woolwich Building Society on retrospective pay rises, the gov.uk maternity pay pages, and HMRC SMP employer guidance.
