How part-time and pro-rata pay work
Pro-rata means your salary is scaled by your working pattern. For example, a full-time salary of £30,000 for 5 days becomes £24,000 for 4 days (80%). Tax and National Insurance apply to your actual pay: you still get the same Personal Allowance and tax bands, but applied to your lower annual income. That often means you keep a higher proportion of your pay than a full-time earner on the same hourly rate, because more of your income stays in the basic rate band.
To get your exact part-time take-home, use the Salary Calculator and enter your annual pro-rata salary (e.g. £24,000 for a 4-day week). For comparing 5 days vs 4 days on the same full-time equivalent salary, use the 4-Day Week Calculator.
Frequently Asked Questions
How is part-time pay taxed in the UK?
Part-time pay is taxed the same way as full-time pay: you get a Personal Allowance (£12,570 for 2025/26), then 20% basic rate, 40% higher rate and 45% additional rate on income above the thresholds. Your employer will apply your tax code and deduct tax and NI based on your actual pay each period. Pro-rata salary simply means your full-time equivalent salary scaled by your working pattern (e.g. 0.8 for 4 days).
How do I calculate my pro-rata take-home pay?
Work out your full-time equivalent (FTE) annual salary, then use a salary calculator to get the take-home for that amount. Your part-time take-home is roughly that result scaled by your FTE fraction (e.g. 4 days out of 5 = 80%). For more precision, enter your actual annual salary (pro-rata amount) into our Salary Calculator — e.g. if you earn £24,000 for a 3-day week, enter £24,000 and you will see your exact take-home after tax, NI, pension and student loan.
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