La guía de abajo aún no está disponible en español y se muestra en inglés. La calculadora está totalmente traducida.
Cómo usar esta calculadora
- Choose the country and tax year. Each country uses its own brackets and allowances; rules are never mixed.
- For the US, choose your filing status, enter gross income and pre-tax deductions such as traditional 401(k) contributions, and choose the standard deduction or enter itemized deductions.
- For the UK, choose England, Wales and Northern Ireland, or Scotland, and enter your gross salary and pension contributions.
- Review the tax in each bracket, your effective rate (tax ÷ gross income) and your marginal rate (the rate on your next unit of income).
Fórmula
Income tax is progressive: each slice of taxable income is taxed at the rate for its bracket, so moving into a higher bracket only affects the income above that threshold. In the UK, the personal allowance falls by £1 for every £2 of income above £100,000, which creates an effective 60% marginal rate between £100,000 and £125,140.
US: taxable income = gross − pre-tax deductions − standard or itemized deduction
UK: taxable income = gross − pension − personal allowance (tapered above £100,000)
Tax = Σ (income within bracket × bracket rate)
US example (2026, single)
- Gross income $85,000 minus $6,000 401(k) = $79,000; minus the $16,100 standard deduction leaves $62,900 taxable.
- 10% on the first $12,400 = $1,240; 12% on $12,400–$50,400 = $4,560; 22% on $50,400–$62,900 = $2,750.
- Federal income tax = $8,550; effective rate ≈ 10.1% of gross income; marginal rate 22%.
Preguntas frecuentes
Which taxes are not included?
For the US: state and local income taxes, credits (such as the child tax credit), the alternative minimum tax, capital gains rates, self-employment tax and newer deductions such as those for seniors, tips and overtime. Payroll taxes are covered by the take-home paycheck calculator. For the UK: dividend and savings income, student loan repayments and the marriage allowance.
What is the difference between effective and marginal tax rate?
The marginal rate applies to your next unit of income. The effective rate is total tax divided by total income, and is always lower because the lower brackets are taxed at lower rates.
Will a raise push me into a higher bracket and reduce my pay?
No. Only the income above the bracket threshold is taxed at the higher rate, so earning more always leaves you with more after income tax.
Where do these rates come from?
US figures come from IRS inflation-adjustment publications (Rev. Proc. 2024-40 and 2025-32, including changes from the One Big Beautiful Bill Act). UK figures come from HMRC and the Scottish Government for 2025/26. Always confirm with official guidance before filing.