Finance⏱ 6 min read
How to Calculate Your Income Tax in the UK
The UK income tax system is tiered — but most people don't know exactly how much they pay or why. Here's a clear, worked calculation for the 2024/25 tax year including NI contributions.
Income tax in the UK is calculated on a tiered band system, similar to a staircase — you pay each rate only on the portion of income in that band, not on your whole salary. Understanding this system prevents confusion and helps you spot errors on your payslip.
The 2024/25 Tax Bands (England, Wales, Northern Ireland)
BandIncome RangeRate
Personal Allowance£0 – £12,5700%
Basic Rate£12,571 – £50,27020%
Higher Rate£50,271 – £125,14040%
Additional RateOver £125,14045%
Three Worked Examples
Example 1: £28,000 salary (basic rate payer)
Personal allowance: £12,570 taxed at 0% = £0
Basic rate band: (£28,000 − £12,570) = £15,430 at 20% = £3,086
Total income tax: £3,086/year = £257.17/month
Example 2: £60,000 salary (higher rate payer)
Personal allowance: £12,570 at 0% = £0
Basic rate band: (£50,270 − £12,570) = £37,700 at 20% = £7,540
Higher rate band: (£60,000 − £50,270) = £9,730 at 40% = £3,892
Total income tax: £11,432/year = £952.67/month
Example 3: £130,000 salary
Personal allowance tapers to zero above £100,000
(reduced by £1 for every £2 earned over £100k)
At £130,000: allowance reduced by £15,000 → allowance = £0
Basic rate band: £37,700 at 20% = £7,540
Higher rate band: (£125,140 − £50,270) = £74,870 at 40% = £29,948
Additional rate: (£130,000 − £125,140) = £4,860 at 45% = £2,187
Total income tax: £39,675/year
National Insurance on Top of Income Tax
National Insurance is a separate deduction, calculated differently:
2024/25 Employee NI rates:
0% on earnings up to £12,570/year (£1,047.50/month)
8% on earnings £12,570 – £50,270/year
2% on earnings above £50,270/year
Example: £60,000 salary
NI-able: £12,570–£50,270 = £37,700 at 8% = £3,016
NI-able: £50,270–£60,000 = £9,730 at 2% = £195
Total NI: £3,211/year
Combined Tax and NI
SalaryIncome TaxEmployee NI
£20,000£1,486£595
£30,000£3,486£1,595
£50,000£7,486£3,011
£60,000£11,432£3,211
£80,000£19,432£3,611
£100,000£27,432£4,011
Effective Tax Rate vs Marginal Rate
Your marginal rate is the rate on the last pound you earn (20%, 40%, or 45%). Your effective rate is total tax divided by total income — always lower than marginal because lower bands are taxed less.
£60,000 earner:
Marginal rate: 40%
Effective income tax rate: £11,432 ÷ £60,000 = 19.1%
Effective combined rate (inc NI): (£11,432 + £3,211) ÷ £60,000 = 24.4%
When people say "I'm a 40% taxpayer," they mean their marginal rate. Their effective rate is typically much lower.