True marginal tax rate visualiser

See how your effective marginal tax rate changes with income. Stack income tax, NI, student loans and the child benefit charge — and spot the 60% trap between £100k and £125k.

Updated for 2025/26
England & Scotland

Your details

£

Your true marginal tax rate

On your next £1 earned at £50k

28%
Income tax 20.0%NI 8.0%

Marginal rate across all incomes

Dashed line: your salary. Hover for breakdown at any income.

£13k: Personal Allowance£50k: Higher rate / NI upper£100k: PA taper starts£125k: Additional rate

What is marginal tax rate?

It's the rate you pay on your next £1 of income — not your average rate. When you cross a threshold (e.g. higher rate, or losing Personal Allowance), your marginal rate can jump well above 45%.

Why does it hit 60% between £100k and £125k?

Between £100,000 and £125,140 your Personal Allowance is reduced by £1 for every £2 of income. That creates an effective 60% marginal rate on that slice (40% income tax plus 20% from the lost allowance). Pension contributions or Gift Aid can lower your adjusted net income and keep you below the trap.

Read more about the 60% tax trap

How student loans stack on top

Plan 2 and most undergraduate plans add 9% on income above their threshold; Plan 3 (postgraduate) adds 6%. So in the 60% taper zone with a Plan 2 loan, your true marginal rate can exceed 70%.

Compare salary sacrifice vs relief at source

Child benefit charge adds even more

The High Income Child Benefit Charge (HICBC) tapers between £60,000 and £80,000 — you lose 1% of your child benefit for every £200 over £60k. That adds several percentage points to your marginal rate if you have children.

HICBC calculator

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True Marginal Tax Rate Calculator UK 2025/26 | TaxRadar