About WorkHourMath
Free, fast calculators for the numbers that end up on your time card and your paycheck.
Why this site exists
Working out hours by hand is surprisingly easy to get wrong: minutes carry at 60, not 100; shifts cross midnight; breaks may or may not be paid; and overtime depends on the workweek and, in some states, the day. WorkHourMath does that arithmetic for you, shows the formula behind every result and explains the rules in plain English, so you can check a time card or a paycheck with confidence.
Who's behind it
WorkHourMath is an independent project built and run by Daniel, who also makes free calculators for home projects and online tools for creators. It isn't owned by a payroll or time-tracking company, and nobody pays to be mentioned in our results.
How we write and check our pages
Every calculator is built from simple time arithmetic and from the published rules — the Fair Labor Standards Act and its regulations, and the laws of the states with their own overtime rules. Pages are researched and drafted with the help of AI tools, then the formulas are checked by hand against worked examples before anything is published. Each page lists its sources and the date it was last updated. Read how we calculate for the details.
We aren't lawyers or payroll professionals, and we say so. Our results are estimates for information; they don't replace your employer's payroll records or legal advice.
How the site is funded
The calculators are free to use. In the future the site may show advertising to cover its costs. Advertising will never change the numbers a calculator gives you.
Get in touch
Spotted a mistake, need a calculator we don't have yet, or want to suggest a better source? Write to hello@workhourmath.com. See also our contact page.