Finance calculators
Income tax calculator
Free income tax calculator for the UK 2026/27 and US federal 2026 tax years, with National Insurance or FICA, band-by-band breakdown and custom brackets for any country.
Inputs
Results
Methodology
Conventions
- Taxable income = gross income − pension contributions − allowance (UK personal allowance or US standard deduction).
- Each band's rate applies only to the income inside that band.
- Marginal rate is the extra tax and contributions on the next unit of gross income.
References
- HMRC, Income Tax rates and allowances
- IRS Revenue Procedure for 2026 inflation adjustments
Formulas
- Tax
- T = \sum_b r_b \cdot \max(0, \min(X, u_b) - l_b)
- UK allowance taper
- PA = \max(0,\ 12{,}570 - \max(0, X_{adj} - 100{,}000)/2)
- Effective rate
- (T + \text{NI or FICA}) / \text{gross}
An estimate for employment income. It ignores Scottish rates, US state and local taxes, credits, other income types and individual reliefs.