Statutory Maternity Pay across all 39 paid weeks.
Your details
Total estimated SMP (39 weeks)
£8,877
Period breakdown
| First 6 weeks @ 90% AWE | £450.00/wk → £2,700 |
| Next 33 weeks (lower of flat rate or 90% AWE) | £187.18/wk → £6,177 |
| Remaining 13 weeks | Unpaid |
| Total SMP | £8,877 |
Interactive scenarios
Tax and deductions, your way
Tax year
Region
Pay schedule
Salary £45,000
Net (monthly)
£2,806
Income tax (monthly)
£541
NI (monthly)
£216
Effective rate
20.2%
The full guide
Worked examples with real figures, the order payroll applies them in, and the traps that catch people out.
Statutory maternity pay runs for thirty nine weeks. The first six pay ninety percent of average weekly earnings, then the standard rate takes over, or ninety percent if that is lower.
Leave lasts fifty two weeks, so the last thirteen are unpaid unless an employer scheme fills them.
Deductions are not a flat set that each take a bite of the same cake. They run in sequence, and the sequence decides the cost of every one after the first.
Pension goes first under salary sacrifice, leaving gross pay before tax and National Insurance ever see it. Under relief at source it leaves net pay instead and HMRC tops the pot up. Same percentage on paper, different payslip.
Income tax then applies band by band against the tax code. National Insurance follows, worked out per pay period rather than across the year. Student loan sits on top of all of it and never reduces taxable pay.
Change the order and the answer changes. That is why a payslip with the same gross as a colleague's can pay a different net.
Pay flow
Gross, pension, tax, National Insurance, net
Average weekly earnings sit near £654, so the first six weeks pay roughly £588 a week before deductions.
From week seven the standard rate applies, which is a substantial drop and the point most household budgets need to have planned for already.
Occupational schemes often top the first few months to full pay in exchange for returning to work, so read the policy before booking the start date of leave.
Worked payslip
Gross to net, line by line
Sample payslip
Month 06 · 2025/26Gross pay
£2,916.67
Pension (5%)
£145.83
Taxable pay
£2,770.84
Income tax
£373.83
National Insurance
£149.52
Net pay
£2,247.66
A tax code change mid year. HMRC adjusts the code, payroll applies it, and the letter explaining it rarely gets read. Check the code on the payslip against the one you expect.
A taxable benefit such as private medical cover. It shrinks the allowance, so a perk raises the tax bill and take home falls in the month it starts.
A switch to salary sacrifice. Gross drops before anything else, which changes every line beneath it and can affect mortgage affordability too.
A bonus month. Income tax evens out across the year through the cumulative system. National Insurance never does.
Rates, bands and thresholds follow published HMRC and gov.uk figures for the 2025/26 tax year, held in one table that every tool reads. April arrives, the table changes, and the results move together.
Earlier years stay available through the year selector, so a late self assessment runs on the numbers that applied at the time rather than today's.
Some cases still need an accountant. K codes carrying negative allowances, bespoke sacrifice arrangements, the annual allowance taper for very high earners, and anything involving two employments at once.
Maternity Pay Calculator answers one question. The salary calculator turns gross into net, the income tax calculator splits the bill by band, the National Insurance calculator shows the step at the upper limit, and the pension calculator prices a percentage change three ways at once.
Every tool reads the same rate table, so two pages never disagree. Run this one, note the figure, then open the next and watch which line moves.
Cash is the floor of a decision, not the decision. An hour a day handed back by a shorter commute is roughly two hundred and fifty hours a year, and nothing prices that against a manager worth working for.
Some benefits convert cleanly. Health cover has a taxable value, a learning budget has a receipt, extra leave has a daily rate. Share options that vest over four years and enhanced parental leave do not, so weigh those separately rather than treating them as salary.
Example gallery
Real inputs, real outputs
Graduate starter
First job, default workplace pension.
Gross / yr
£28,000
Pension
5%
Income tax
£3,086
NI
£1,234
Mid career
Standard tax code, modest pension uplift.
Gross / yr
£45,000
Pension
6%
Income tax
£6,486
NI
£2,594
Higher rate
Crossing the higher rate band.
Gross / yr
£72,000
Pension
8%
Income tax
£16,232
NI
£3,451
Scotland mid
Scottish bands applied.
Gross / yr
£45,000
Pension
5%
Income tax
£6,928
NI
£2,594
About this calculator
Statutory Maternity Pay (SMP) is paid for up to 39 weeks. The first 6 weeks are 90% of your average weekly earnings; the next 33 weeks are the lower of £187.18 per week or 90% of AWE.
Quick reference
Questions are added here as readers send them in.