Maternity & Sick Pay Calculator — Take-Home Pay Impact

How is your leave-period take-home pay calculated?

The calculator works by breaking your leave period into its component daily rates, building a representative monthly gross figure, then running the full PAYE deduction chain against that reduced income. Because PAYE is applied cumulatively through the year, your tax code's personal allowance still protects your income — meaning a lower-paid month benefits proportionally more from that allowance than a higher-paid month.

The "annual equivalent" step is how PAYE works in practice: your employer calculates each month's tax by projecting your current month's gross across the full year, then applies a twelfth of the resulting annual tax bill. This means a month of low pay results in lower income tax in that month, and you may recover over-paid tax later in the year through the cumulative nature of PAYE.

Step-by-step walkthrough

Start with your daily rate: a £35,000 salary working 5 days a week, 52 weeks a year produces a daily rate of £134.62. In a month where you work 11 days at your company's full maternity rate (100%) and spend the remaining 10.75 working days on flat-rate SMP of £37.44/day, your monthly gross is roughly £(11 × £134.62) + (10.75 × £37.44) = £1,481 + £403 = £1,884. Annualised, that's £22,608. Against that income, the 2025/26 personal allowance of £12,570 leaves only £10,038 taxable, creating an income tax bill of around £2,008 per year — just £167 per month. National Insurance on £22,608 is approximately £806 per year (£67/month). Your normal month on £35,000 would see you paying around £4,686 income tax and £1,806 NI annually. The comparison makes the monthly drop vivid.

Emma's scenario — a Manchester teacher earning £38,000

Emma takes 6 months of maternity leave. Her employer pays full salary for the first 4 weeks, then SMP at the flat rate (£187.18/week) for the remaining period. In her SMP months, her monthly gross is approximately £748 — compared to a normal gross of £3,167. After income tax, NI, and her 6% salary sacrifice pension contribution, her normal take-home is £2,236 per month. During the SMP months she pays virtually no income tax or NI (her income falls below the primary threshold when annualised), and her pension contribution is maintained at the full 6% of her normal salary by employer policy — giving her a leave-month take-home of around £748 gross with only pension deducted. This calculator helps Emma plan her savings buffer before leave begins.

Understanding your maternity leave take-home pay in the UK is crucial for financial planning. Many employees are surprised to find that tax and NI deductions virtually disappear during SMP-only months — because the SMP rate of £187.18/week annualises to just £9,733, which is below both the income tax personal allowance and the NI primary threshold. See our UK Salary Calculator for your normal-month baseline, or our Hourly to Salary Calculator if your pay is quoted per hour.

What does my result mean?

The side-by-side comparison shows you two things: the absolute drop in take-home pay, and exactly which deductions change. For most people planning how much sick pay they will receive, the answer involves three numbers — your company sick pay (if any), Statutory Sick Pay, and the PAYE deductions that still apply. SSP of £118.75/week (2025/26) annualises to £6,175 — below both the personal allowance and the NI primary threshold — meaning that on SSP alone you will pay no income tax or NI. Your net SSP take-home is effectively the gross figure.

What if your result shows a very small or zero deduction on leave?

This is expected when your leave-period income falls below the personal allowance threshold of £12,570. The tax system gives each taxpayer the full personal allowance across the year. If you earn very little during a leave month, that month's PAYE calculation produces near-zero tax, and you may even receive a repayment if you overpaid tax earlier in the year. The one deduction that does continue regardless is pension, unless you suspend contributions — use the "Maintain full pension during leave" toggle to see the difference.

What are the most common mistakes when estimating maternity pay?

The first mistake is confusing statutory and contractual maternity pay. SMP is the legal floor; your employer may offer significantly more. Always check your contract or ask HR before planning a budget. The second is forgetting that SMP is taxable — while the tax may be minimal at the flat rate, it is not zero if your income from other sources (e.g. a working partner's use of your allowance via Marriage Allowance) is not considered. The third is assuming pension contributions pause automatically; in most cases your employer pension continues at the SMP rate unless you actively opt out, meaning your pension pot keeps growing even on reduced pay — but your take-home is slightly further reduced. For a deeper understanding of how student loan repayments interact with reduced pay, see our Salary Calculator.