What does the next £1 of salary actually become?

Combines income tax, employee National Insurance, the £100k personal-allowance taper and any active student loan plans. Shows your full take-home plus the effective marginal rate on the very next pound of salary — the number that explains why a £10k raise sometimes feels like £4k.

Your scenario

£
Student loan plans you hold

Take-home

Gross
£50,000
Net (annual)
£39,520
Per month
£3,293
Income tax
−£7,486
National Insurance
−£2,994

Next £1 of salary

What you actually keep of every additional pound at this salary.

Marginal rate
28.0%
You keep
72.0% (≈£1 per £1)
Income tax 20.0%
NI 8.0%
Loans 0.0%
PA taper 0.0%

Methodology and sources

  • Income-tax bands and the £100,000 personal-allowance taper from gov.uk Income Tax — 2025-26 rates for England, Wales and Northern Ireland. Scottish income tax uses different bands (Starter / Basic / Intermediate / Higher / Top) and is not yet modelled.
  • National Insurance rates from gov.uk National Insurance — employee Class 1 (8% main rate, 2% above the Upper Earnings Limit).
  • Student-loan rates are taken from the same plan constants used by the student loan calculator.
  • The "marginal rate" is computed as the actual difference in tax + NI + loans between your salary and your salary + £100, then expressed per pound. This handles band edges and the PA taper correctly without analytical hand-waving.