Payrollmath is a free set of calculators for the decisions that come with a number attached. What a paycheck is actually worth after withholding, what a bonus leaves you with, which months hold three of them. No sign-up, no paywall, and no email address required to see an answer.
The idea is to show the working
Most calculators on the internet give you a figure and stop. That is fine until the figure looks wrong, and then you have no way to find out whether the tool is mistaken or your assumption is. Every calculator here breaks its answer into the parts it was built from, so you can see which input is driving the result and check the one line you doubt.
It is also why the explanations sit on the same page as the tool rather than in a blog post somewhere else. The thing worth knowing about a paycheck calculator is usually why two calculators disagree, and that belongs next to the number.
Where the numbers come from
Tax and payroll figures come from primary sources: IRS publications for federal withholding, and each state’s own revenue or treasury department for state rates, allowances and payroll deductions. Rates are held in dated files, so a page can say which year it is working from rather than leaving you to guess.
This matters more than it sounds. Several states changed their withholding in the middle of 2026, and at least one government page still publishes a superseded multiplier. Where a state has done something unusual, the page says so.
What this site does not do
- It does not ask you to create an account.
- It does not store what you type into a calculator. The figures you enter are used to work out an answer and are not saved to any record.
- It does not give financial, tax or legal advice. These are estimates, built carefully, and they are not a substitute for a professional who knows your circumstances.
Payrollmath is independent. It is not affiliated with any bank, lender, payroll provider, insurer or government agency, and nobody pays to be featured here.
Corrections
If a number here looks wrong, please say so. Tell us which calculator, what you entered and what you expected, and we will check it against the source. Write to info@payrollmath.com. Corrections to the underlying math are treated as bugs and fixed for every page that shares the engine.