About ClockInMath
ClockInMath is an independent project owned and run by Matt, a person, not a company or news organization. It is a free, no-signup tool site: Hours in. Pay out. Printable timesheet.
Purpose
I built ClockInMath to help people work out hours worked, decimal hours, overtime and gross pay on a timesheet with real numbers instead of guesses. The calculators run in your browser, show their formulas, and let you change every assumption. The guides explain the numbers behind the tools in plain language.
Data sources
Hours are worked out from the clock times you type (out minus in, minus unpaid breaks, overnight shifts roll into the next day). Overtime rules follow the U.S. Department of Labor's Fact Sheet #23 (FLSA: time-and-one-half after 40 hours in a workweek) and the California Department of Industrial Relations overtime FAQ (daily overtime and double time). Your hours, rate and the overtime rules that apply to you are your own inputs; state and local laws, union contracts and employer policies can differ. ClockInMath is currently served at matt5516.github.io/time-card-calc; clockinmath.com is the planned domain, pending the owner's approval.
How we keep it accurate
The math is covered by automated tests with hand-computed answers, figures show their source and update date where possible, and the site was last updated October 15, 2026. If you spot an error, please tell me and I will fix it.
Disclaimers
Estimates only, not legal, tax or payroll advice. Overtime rules vary by state, employer and job; check with your employer or your state labor department. Gross pay is before taxes and deductions. ClockInMath is currently at matt5516.github.io/time-card-calc; clockinmath.com is the planned domain, pending the owner's approval. Not affiliated with any payroll provider. See the terms of use and privacy policy.
Contact and feedback
Email matt63sorensen@yahoo.com, use the Feedback button on any page, or open an issue on GitHub. More on the contact page.