Job offer comparison calculator (UK)
Compare your current role and an offer on real 2026/27 take-home maths — then on the half of the decision a payslip can't show: hours, wellbeing, growth, security and flexibility, weighted by what matters to you. Free, no signup, nothing you type leaves your browser.
What a real comparison looks like
The calculator's built-in example: £52,000 with salary-sacrifice pension against an offer of £62,000 plus bonus on a net-pay scheme. The gross gap says +£13,000. The payslips say:
Current — £52,000 + £2,000 bonus
salary sacrifice · Plan 2 · 5% pension
Offer — £62,000 + £5,000 bonus
net pay · Plan 2 · 4% pension
£13,000 of gross becomes £7,794 of real annual advantage once the deduction stack, both pension schemes, bonus likelihood and the longer commute are priced. The break-even figure says this offer could fall to £47,726 and still match the current deal — the single most useful number in a negotiation.
The same example, on the life axis
The payslips are only half the verdict. The same two jobs, scored on what the money can't show — and in this example the life side argues against the move:
Current role — the day-to-day
hybrid, 3 office days · the setup you prefer
New offer — the day-to-day
on-site five days · rated after meeting the team
The offer is genuinely more enjoyable and a real step up (wellbeing +0.90, growth +1.95 after the met-the-team discount) — but it takes 314 more hours of the year (time −3.14), feels less secure (−0.60), and moves to five office days against a hybrid preference (flexibility −1.60). The life axis lands at −0.31: a quiet, honest "this costs you something". The verdict weighs both sides by your priorities — money +2.92 and life −0.31 combine to +1.43: "slightly greener — switch", with the card saying in words that money is carrying it, and a steadiness check confirming the answer survives all 20 what-ifs tested.
What a full comparison checks
The full 2026/27 deduction stack: income tax for England/Wales/NI and Scotland, employee NI, all five student-loan plans (they stack if you have more than one), and your pension under its real mechanism — salary sacrifice, net pay or relief at source, which can move take-home by hundreds of pounds on identical contributions.
The things that never appear on a payslip: the employer pension contribution (deferred pay, but real pay), commute cash paid from after-tax money, bonus likelihood, and the hours the job actually takes — contracted plus commute — so every offer is also priced per committed hour.
The life axis: stress, enjoyment, evenings and on-call become a wellbeing score; skills and promotion path a growth score; plus security and how each setup fits the one you actually want. Rated claims about a job you have not done yet are discounted by how well you really know it. The verdict combines the two axes only through your own priorities — exactly as the worked example above shows. Every formula is on the methodology page, and the engine re-verifies hand-calculated cases live in the page.
Run your own numbers
The calculator opens with a fully worked example — change anything and every figure recomputes live, in your browser. Nothing you type is uploaded.