A pay rise is not worth its face value. By the time tax and National Insurance have taken their share, and the real purchasing power impact of inflation is accounted for, the amount you actually keep is consistently smaller — sometimes significantly smaller — than the headline percentage implies. Here is how to calculate what you genuinely receive.
Net vs Gross Income
Gross income is what your employer pays. Net income is what arrives in your bank account after PAYE deductions. The difference between a gross pay rise and a net pay rise depends on your current salary band and which tax and NI rates apply to the additional income.
For a salary within the basic rate band (£12,570 to £50,270 in 2024/25), each additional pound of gross income results in approximately 72p net, after 20% income tax and 8% employee NI.
For a salary in the higher rate band (£50,270 to £100,000), each additional pound is worth approximately 58p net, after 40% income tax and 2% NI.
For earnings between £100,000 and £125,140, where the personal allowance tapers out, the effective marginal rate reaches 60%. Each additional £1 of gross income is worth approximately 40p net.
A £5,000 pay rise therefore delivers:
- £3,600 net if you remain in the basic rate band
- £2,900 net if you are in the higher rate band
- £2,000 net if you are in the personal allowance taper zone
Use the Pay Rise Real Impact Calculator to find the exact net change for your specific starting salary and rise amount. The tax system's non-linearity means the same gross figure produces very different outcomes depending on where you start.
Real Gains
Even after calculating the accurate net figure, the real gain requires one further adjustment: inflation. The net increase in take-home pay represents more purchasing power only to the extent that it exceeds the rate at which prices are rising.
If your net pay rises by £180 per month and inflation is running at 3.5%, your existing salary has lost approximately 3.5% of its purchasing power over the year. In absolute terms, you need a certain amount just to stand still — and only what exceeds that represents a genuine improvement.
For a £42,000 salary in a 3.5% inflation environment, the amount required just to maintain purchasing power is approximately £1,470 gross per year, or around £1,060 net. A £2,000 net pay rise in these conditions represents roughly £940 of genuine real improvement — less than half the nominal figure.
Hidden Reductions
Several specific scenarios reduce the effective value of a pay rise beyond the standard tax and inflation adjustments.
Student loan repayments: Plan 2 student loans charge 9% on earnings above £27,295. A pay rise that sits above this threshold is effectively taxed at an additional 9%, reducing the marginal retention rate for basic rate taxpayers from approximately 72% to 63%. The loan repayment does reduce the outstanding balance, but it is still a cash flow reduction that most pay rise calculations ignore.
Benefits withdrawal: Some means-tested benefits — child tax credits, Universal Credit, free childcare hours — are reduced or withdrawn as income rises. In some cases, a gross pay rise of £2,000 can trigger a benefits reduction larger than the net pay increase, producing an effective marginal rate above 100%. Anyone in this position should model the net impact carefully before accepting a pay rise without also negotiating adjustments to other elements of compensation.
Pension contribution increases: Defined contribution pensions with employer matching often work as a percentage of salary. A pay rise that increases both employee and employer contributions is partly absorbed by the pension — which is not a loss, but it does reduce the immediate take-home impact.
What This Means in Practice
The practical implication of understanding the real value of a pay rise is that decisions made assuming the gross figure — "I can afford the upgrade because I'm earning more" — are consistently overoptimistic. Budgeting from the net figure, adjusted for any new obligations the rise creates, produces more accurate planning.
It also reframes salary negotiations. If a £50,000 salary and a £54,000 salary produce similar net take-home due to the higher rate band ticking in, the negotiating emphasis might shift to pension contributions, additional leave, or other non-cash compensation where the tax efficiency is higher. Knowing what you actually keep changes what is worth negotiating for.