About TimeCalculator.Tools
TimeCalculator.Tools is a set of free calculators for hours, work time, timesheets, shifts and time conversions — built to be fast, accurate and private.
What this site does
The calculators cover the everyday time questions people actually ask: how long did I work, how many hours is 09:00 to 17:30, what is 7 hours 25 minutes in decimal, how many overtime hours are in a 43.5 hour week. Every tool shows its arithmetic clearly and lets you copy, print or export the result.
Who it is for
Employees filling in a time card, freelancers tracking billable hours, shift workers with overnight schedules, managers checking a weekly timesheet, and anyone who needs a precise duration without opening a spreadsheet.
How the calculations are designed
Clock times are converted to whole seconds before any arithmetic, and decimal hours are produced only for display. Rounding is optional and deterministic. Overtime splitting is simple weekly arithmetic — the calculators do not make employment-law decisions. The methodology page documents the formulas in detail.
Privacy-first approach
Everything is calculated in your browser. The times you enter are never uploaded and are never sent to analytics — analytics only records anonymous product events, such as the fact that a calculation was completed or a CSV was downloaded.
Report an error
If a result looks wrong, please tell us — arithmetic bugs are taken seriously here. See the contact page for how to reach us, including what to include in your message.