How Federal Income Tax Works
The US uses a progressive tax system — you don't pay one flat rate on all your income. Instead, each portion of your income that falls within a bracket is taxed at that bracket's rate. This is why your effective rate (total tax ÷ total income) is always lower than your marginal rate (the bracket your last dollar falls into).
Standard Deduction for 2026
Before calculating tax, the IRS subtracts a standard deduction from your gross income. For 2026, this is approximately $15,000 for single filers and $30,000 for married filing jointly — these figures adjust annually for inflation.
Frequently Asked Questions
For single filers: 10% up to $11,925, 12% up to $48,475, 22% up to $103,350, 24% up to $197,300, 32% up to $250,525, 35% up to $626,350, 37% above. Married filing jointly thresholds are roughly double.
Marginal rate is your highest tax bracket. Effective rate is your total tax divided by total income — always lower, since only income within each bracket is taxed at that bracket's rate, not your entire income.
No, this calculator estimates federal income tax only. State tax varies from 0% (nine states have none) to over 13% in California's top bracket — check your state's specific rates separately.