Quirkulator

Duration Calculators

10 calculators covering time arithmetic across hours, minutes and seconds, each with its formula and worked examples.

Duration Calculators brings together 10 calculators for time arithmetic across hours, minutes and seconds, including Add Time Calculator, Countdown Timer Split, Hours and Minutes to Decimal and Subtract Time Calculator.

These are separate pages rather than one tool with a mode switch because the inputs differ, the interpretation differs, and the question behind each one is different. Each page opens with the formula it uses, defines every variable, and walks the calculation through real numbers before you type anything.

All 10 pages compute in your browser: nothing you type is sent anywhere, and results update as you edit. Each one carries worked examples, interpretation bands where a score needs context, and a FAQ answering what people actually ask about that calculation.

The collection is part of Date & Time, and every page links to the neighbouring calculations you usually need next.

10 pages in this collection

Add Time CalculatorAdd two durations in hours and minutes and see when the combined block would finish.Average Time CalculatorFind the mean of a list of durations, with the spread and the median alongside it.Countdown Timer SplitDivide a fixed block of time into equal segments and get the clock time each one starts.Decimal Hours to TimeTurn a decimal hours figure back into readable hours and minutes.Hours and Minutes to DecimalConvert a time written as hours and minutes into the decimal hours payroll systems expect.Lap Time Average CalculatorAverage a set of lap times to the hundredth of a second and see the spread and pace.Subtract Time CalculatorWork backwards from a finishing time to find when a task of a given length must start.Time Duration CalculatorMeasure the elapsed time between two clock times, including spans that cross midnight.Time Zone Offset CalculatorConvert a clock time between two UTC offsets and see whether the date changes.Total Hours CalculatorAdd up a whole list of durations at once and get the total in hours and minutes.

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