Progressive tax systems apply higher rates only to the income within each bracket, not your entire income at the top rate. This calculator uses real, sourced tax rules for each supported country to show exactly how that adds up — see the tax data source note on this page for exactly where the figures come from.
Effective rate vs. marginal rate
Your marginal rate is what you pay on your last dollar earned. Your effective rate — what actually matters for 'how much of my income goes to tax' — is always lower, because earlier income was taxed at lower bracket rates first.
What this doesn't include
This covers income tax only. Payroll-style taxes (US FICA, Canadian CPP/EI, UK National Insurance), state/provincial variations beyond what's noted, and personal credits or deductions beyond the standard ones aren't included — see this country's specific disclaimer above.