Why a flat-rate estimate is wrong
A US single filer at $90,000 in 2024 owes roughly $14,000 in federal income tax — an effective rate of about 15.6%, not 22% (the marginal bracket) and not 12% (the first-bracket rate). Using either as your "tax rate" when making decisions (should I take the bonus, should I convert to Roth?) is a common error. The table on the right shows the truth.
FAQ
Why isn't social security / national insurance included?
Because it's a separate tax with its own cap and rules, and including it confuses the marginal-vs-effective story. US FICA is 7.65% on the first ~$168k of wages; UK National Insurance is 8% above the primary threshold. The Salary Converter handles payroll deductions; this tool is for income tax only.
Why no state tax (US)?
Because state tax is a parallel system with its own brackets and 0% states. Add your state's top marginal to the federal top marginal to get a rough combined picture. For a precise state estimate, see your state's Department of Revenue site.
Why is China on this list and how is it different?
China's IIT (Individual Income Tax) has 7 brackets from 3% to 45%, with a monthly standard deduction of 5000 RMB. The annual equivalent is shown here. China's system also has a different treatment of "comprehensive income" (wages, author fees, royalties) vs "business income". This calculator models the comprehensive income path.
Methodology & sources
Brackets (2024/2025): US IRS Rev. Proc. 2023-34 (single & MFJ); UK HMRC 2024/25 Scotland & rUK rates; DE BMF 2024 Einkommensteuergesetz §32a; CA CRA 2024; ATO 2024/25 Stage 3; India Finance Act 2024 (old regime, default); JP NTA 2024; China MOFT 2024 IIT law. The model assumes standard deduction / personal allowance is taken, no other credits, and no investment or self-employment income. State, local, and FICA/NI are out of scope. This is an estimate, not a return. Verify with a qualified tax professional before filing.