Compare two offers using the same deduction assumptions and see the real monthly delta.
Updated for 2025/26 · Reviewed by James Whitfield · Methodology and assumptions
A £5,000 gross salary increase does not produce £5,000 more to spend each year. Because the UK income tax system is progressive, a pay rise pushes earnings further into higher marginal rate bands. At a salary of £40,000 in England, the marginal rate on extra earnings is 32% (20% Income Tax + 12% NI). At £50,000 it remains 32%, but above £50,270 the marginal rate rises to 42% (40% tax + 2% NI). Above £100,000 it reaches 62% because every £2 earned between £100,000 and £125,140 removes £1 of personal allowance, creating an effective 60% rate on that slice.
This means that when you compare two offers, the monthly take-home difference is always smaller than the gross difference would suggest. A £45,000 offer versus a £40,000 offer appears to be a £5,000/year gross improvement, but the additional £5,000 is taxed at around 32%, leaving approximately £3,400 more per year net — about £283/month extra, not £417.
The comparison tool above applies the full 2025/26 PAYE calculation to both salaries using identical assumptions (same region, student loan plan and pension percentage), so the monthly delta shown is the real, after-tax difference.
The table below shows net monthly take-home for common salary pairs in England, using tax code 1257L, NI category A, no student loan and no pension contributions. Use the calculator above for your exact figures with real deduction settings.
| Offer A | A monthly net | Offer B | B monthly net | Extra per month |
|---|---|---|---|---|
| £30,000 | ~£2,003 | £35,000 | ~£2,295 | +£292 |
| £35,000 | ~£2,295 | £40,000 | ~£2,586 | +£291 |
| £40,000 | ~£2,586 | £45,000 | ~£2,869 | +£283 |
| £45,000 | ~£2,869 | £50,000 | ~£3,116 | +£247 |
| £50,000 | ~£3,116 | £60,000 | ~£3,616 | +£500 |
| £60,000 | ~£3,616 | £75,000 | ~£4,255 | +£639 |
| £75,000 | ~£4,255 | £100,000 | ~£5,182 | +£927 |
Monthly estimates using 2025/26 rUK PAYE rates (tax code 1257L, NI category A, no student loan, no pension). The £45k–£50k step appears smaller because the higher-rate threshold (£50,270) has not yet been crossed — earnings at both levels are fully in the 20% band. The £75k–£100k gain includes part of the personal allowance taper zone (62% effective marginal rate on £100k–£125,140), which is why each gross pound above £100k produces less than half its face value in take-home.
When comparing a new offer against your current salary, enter both gross figures with the same pension and student loan settings. The monthly delta is the actual cashflow change, which is what matters for budgeting. If the new role is in Scotland and your current role is in England, use different region settings for each — Scottish income tax above £43,662 is higher, so the same gross salary produces a lower net in Scotland.
If you are asking for a pay rise, use the tool to calculate what monthly improvement you actually need. If you want an extra £300/month net, you typically need to ask for a larger gross figure than £3,600/year — because the extra earnings are taxed at your marginal rate. At a salary of £40,000, £300/month net requires approximately £5,300/year gross (at 32% marginal rate).
If a role offers different salaries depending on location (London vs regional, for example), enter the two offers with the same region to isolate the gross difference impact. If you are considering moving to Scotland for a role that pays the same salary as a comparable role in England, compare them with different region settings to understand the Scottish income tax premium.
Two offers with the same gross salary but different employer pension contributions are not equivalent. Enter both with their respective employee pension percentages to compare the take-home. Also note that salary sacrifice pension contributions save both Income Tax and NI on the contributed amount — an offer with a 5% salary sacrifice pension scheme may produce lower take-home than one without, but the pension pot difference compounds significantly over a career.