Time Calculator

This calculator handles three common time problems in one tool: working out the duration between two times, adding a length of time to a starting point, or subtracting a length of time from it. Choose the mode you need from the tabs above. For duration, enter a start time and an end time, and tick the overnight box if the end falls the next day, handy for night shifts that run past midnight. For the add and subtract modes, enter a starting time and the hours and minutes you want to add or take away. The calculator instantly returns the answer as a large headline figure, plus a full breakdown showing hours and minutes, decimal hours, total minutes and total seconds, with a plain-English summary of the result. Decimal hours are especially useful if you run timesheets or invoice by the hour, since 1 hour 30 minutes converts cleanly to 1.50 hours for multiplying against an hourly rate. The tool works in 24-hour time internally, and it automatically rolls the result over to the next or previous day where needed, so overnight shifts and early starts calculate correctly without manual adjustment. It suits payroll, rostering, cooking timers, appointment planning, and any situation where you need an exact elapsed time rather than a rough guess.