How our calculators work

Every number on PaydayMath comes from a published government rule. This page explains the formulas we use, where the rates come from and how we keep them current. Rates were last reviewed on October 19, 2026.

Our review process

1. Primary sources first. Federal rates come from IRS Publication 15 (Circular E) and Revenue Procedure 2025-32. Social Security limits come from the Social Security Administration. Overtime and minimum wage rules come from the U.S. Department of Labor and each state's labor department.
2. Cross-check. State withholding rates are compared against at least one payroll industry reference. When sources disagree, we follow the state's own publication.
3. Test cases. Each calculator is checked against worked examples by hand before it goes live, including edge cases such as wages above the Social Security limit or more than 12 hours in a day.
4. Yearly update. Every January we update federal rates, state rates and minimum wages, and we fix any rule that changes mid-year as soon as it is published.

Bonus tax calculator

Bonuses are "supplemental wages". We use the IRS percentage method, the one most employers use:

• Federal income tax: 22% of the bonus, or 37% on the part of your supplemental wages above $1 million in the year.
• Social Security: 6.2%, only on wages up to the yearly limit ($184,500 in 2026). If you enter your earnings so far this year, we stop Social Security at the limit.
• Medicare: 1.45%, plus 0.9% on wages over $200,000.
• State: the state's supplemental rate when it publishes one, otherwise its flat rate or an estimate based on its brackets, as noted on each state page.

The "gross up" option works backwards: it finds the bonus you need to pay so that the employee receives an exact amount after withholding.

Overtime calculator

Hours over 40 in a workweek are paid at 1.5 times the regular rate, as the Fair Labor Standards Act requires. For states with daily rules we apply them first and avoid counting the same hour twice: California (over 8 hours a day, double time over 12, and the seventh consecutive day), Alaska (over 8 hours a day), Nevada (over 8 hours a day when the rate is below 1.5 times the state minimum wage) and Colorado (over 12 hours a day).

Time card calculator

We convert each clock-in and clock-out time to minutes, subtract unpaid breaks, handle shifts that cross midnight and add up each day. Weekly overtime is counted in 7-day blocks, so a two-week pay period is split into two workweeks. Decimal hours are minutes divided by 60.

Hourly to salary calculator

Yearly pay is the hourly rate times hours per week times weeks worked. To estimate take-home pay we subtract the 2026 standard deduction for a single filer, apply the federal brackets from Revenue Procedure 2025-32, then subtract Social Security, Medicare and a state estimate. It assumes no other income or deductions.

What we don't include

Local and city taxes, pre-tax deductions such as 401(k) or health insurance, and your specific W-4 choices are not part of the estimates unless a calculator asks for them. That is why results are estimates of withholding, not your final tax bill.

Who we are

PaydayMath is a small independent team that builds payroll calculators and writes plain-English guides about how U.S. pay works. We are not affiliated with the IRS, any state agency or any payroll company. The site is free and supported by ads; advertisers have no say in our content.

Report a mistake

If a number looks wrong, email hello@paydaymath.com with the page and the case you tried. We check every report and update the page and its date when we fix something.