Methodology
How we calculate the numbers
The whole point of this site is that the numbers are right. Anyone can build a salary calculator; the difference is whether you can trust what it tells you. This page explains exactly where every figure comes from, what we assume, and when we last checked it against the source.
Our principle: primary sources only
We never copy figures from other calculators or summary blogs — that's how errors spread. Every tax band, National Insurance threshold, benefit rate, student-loan threshold and US federal or state figure is taken directly from the body that sets it. Where an official page exists, we link straight to it.
How UK take-home pay is worked out
For a standard employee (Class 1 National Insurance) we apply, in order: your Personal Allowance, the Income Tax bands for your region (England, Wales and Northern Ireland, or the separate Scottish bands), National Insurance, any student loan plan you select, and pension contributions. The Personal Allowance tapers away above £100,000, which we model — that's what creates the 60% effective marginal rate between £100,000 and £125,140.
Thresholds are frozen until April 2031 (extended at the Autumn Budget 2025), and our figures reflect that freeze. Pensions can be treated as salary sacrifice or relief at source, because the two are taxed differently, and you can switch between them.
How UK benefits are worked out
Universal Credit, PIP, DLA and Attendance Allowance use the current DWP rates and, for Universal Credit, the current elements, taper and work allowances. We keep these in step with benefit uprating, which is normally announced in the autumn and takes effect the following April.
How US paycheck figures are worked out
US pages apply federal income tax brackets, FICA (Social Security up to the annual wage base, plus Medicare and the Additional Medicare surtax), and state income tax using each state's own rules — including the states with no income tax. 401(k) and 1099 self-employment figures use the current IRS limits and the self-employment tax rules.
The UK sources we verify against
- HMRC — Income Tax rates and allowances
- HMRC — National Insurance rates
- Student Loans Company — repayment thresholds
- DWP — Universal Credit rates
- DWP — PIP, DLA and Attendance Allowance rates
- ONS — Earnings and hours worked
- HMRC — Stamp Duty Land Tax
The US sources we verify against
- IRS — Federal income tax brackets
- IRS — Social Security & Medicare (FICA) rates
- Social Security Administration — wage base
- IRS — 401(k) contribution limits
What we don't do
We don't give personal financial advice, and we're not accountants. Our calculators are accurate estimates for a set of clearly-stated assumptions — they can't know the specifics of your tax code, your employer's payroll quirks, or a mid-year change. For anything that carries real financial weight, check the official source we've linked or speak to a qualified adviser.
Who's behind these figures → Meet the team that builds and checks the calculators.Quick answers
Are these figures official?
Every rate and threshold is taken from official primary sources — HMRC, the DWP, gov.uk, the ONS and, for US pages, the IRS and state revenue departments. We link to each source below so you can check for yourself.
How often are they updated?
We re-check figures whenever the rules change — at each UK Budget, the April tax-year rollover, and when benefit uprating is announced. UK figures currently reflect the 2026/27 tax year; US figures reflect 2026. Last verified 12 August 2026.
Why might your figure differ from my payslip?
Payslips vary with your exact tax code, pension type (salary sacrifice vs relief at source), student loan plan, mid-year changes and region. Our calculators let you set these, but a real payslip reflects your specific circumstances. Treat our figures as accurate estimates, not a payslip.
Written in plain English by mytakehome.money. General information, not financial advice — check anything important at gov.uk or with a qualified adviser.