Income tax can be confusing, with multiple bands, allowances, and thresholds that change depending on your income level and country. This income tax estimator calculates your estimated tax liability for the UK or US based on your total annual income, applying the correct personal allowance or standard deduction and tax bands or brackets. It shows a band-by-band breakdown of how much tax you pay at each rate, plus your overall effective tax rate, useful for understanding marginal vs. average tax rates. Self-employed individuals, freelancers, and employees alike can use this tool to estimate their tax bill before filing an official return.