What format should I use?

Use hours:minutes (e.g. 2:30 for 2 hours 30 minutes). You can add or subtract multiple times.

Either use H:MM format (e.g. 1:45) or decimal hours (e.g. 1.75). The result is shown as hours:minutes.

Online Hours Calculator

Add or subtract time in hours and minutes. Enter times like 2:30 or 1:45 to get total hours:minutes.

Time 1 (e.g. 2:30)

Time 2 (e.g. 1:45)

What format should I use?: Use hours:minutes (e.g. 2:30 for 2 hours 30 minutes). You can add or subtract multiple times.
Can I use decimals?: Either use H:MM format (e.g. 1:45) or decimal hours (e.g. 1.75). The result is shown as hours:minutes.

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Convert Celsius to Fahrenheit and Fahrenheit to Celsius instantly. Free temperature converter.

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Calculate C(n,r) — the number of ways to choose r items from n without order. Uses n!/(r!(n-r)!).

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Calculate the number of ways to choose r items from n with repetition allowed. Formula: C(n+r-1, r).

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Count how many permutations of n objects are even (expressible as an even number of swaps). For n ≥ 2, equals n!/2.