The time calculator
that just adds up.

Put a + between the durations, like "5h 30m + 2h 15m", and you get 7 Hours 45 Minutes. Mix any units you like (days, hours, minutes, seconds) and choose how the answer reads with the format picker.

Use a minus sign. "8h - 90m" gives 6 Hours 30 Minutes, and "2 days - 4h" gives 1 Day 20 Hours. It subtracts across units, so you never have to convert everything to minutes first.

Yes. Pair a number with × (or *) and ÷ (or /). "8h 15m × 3" gives 24 Hours 45 Minutes, and "1 day ÷ 4" gives 6 Hours. Handy for shifts, billing, or splitting time evenly.

Years, months, weeks, days, hours, minutes, seconds, and milliseconds. Type the full word or the shorthand (h, m, d, w, s), like "1w 3d", "90 min", or "1d 4h 30m". Months take "mo" so they don't clash with minutes.

The web version is free to use and is supported by ads. The Android app is free with no ads, with an optional donation if you want to support it. On iOS, a Pro upgrade unlocks the full app. Whichever you use, the calculation runs entirely on your device.

Yes. The site runs the very same engine as the Cardamon apps, compiled for your browser, so the answer you get here matches the app down to the millisecond.

Every number needs a unit. "2 + 2" is ambiguous, but "2h + 2h" gives 4 Hours and "2d + 2h" gives 2 Days 2 Hours. The only bare number allowed is the multiplier or divisor, like the 3 in "8h 15m × 3". Always attach a unit to each value.

Open the format picker and pick how the answer reads. Options include Hour Minute, Hour Minute Second, Day Hour Minute, Minute, Second, and Week Day. The same total stays fixed; only the wording changes, so "450 minutes" can show as 7 Hours 30 Minutes or 450 Minutes.

Type your calculation, then choose the Minute Second format from the picker. "3m 45s + 90s" becomes 5 Minutes 15 Seconds. You can also pick plain Second to read it as 315 Seconds, or Hour Minute Second for longer durations. The format only changes how the answer is displayed.

Yes. The web version runs entirely in your browser using the compiled calculation engine, so it keeps working with no connection once the page has loaded. The calculation never leaves your device. The Android and iOS apps run fully offline too.

It depends on the platform. The Android app is free and has no ads. The web version is free to use and is supported by ads. On iOS, you unlock the full version with a Pro purchase instead of ads. In every case the calculation runs on your device.

Yes. When you subtract a larger duration from a smaller one, the result goes negative. "30m - 2h" gives -1 Hour 30 Minutes. This is useful for tracking deficits, like time over or under a budgeted total, without forcing you to reorder the durations yourself.

Yes. Milliseconds are a supported unit, written as "ms". You can add, subtract, multiply, or divide them like any other unit, for example "1s - 250ms" gives 750 Milliseconds. It is one of the few time calculators that goes down to the millisecond, which audio and dev users rely on.

Type your durations, then choose the single Hour format from the picker. "8h 15m" reads as 8.25 Hours, and "90 min" reads as 1.5 Hours. Values that don't divide evenly show seven digits, so "1h 20m" becomes 1.3333333 Hours. Great for payroll and timesheets.

Enter each clock time as a duration from midnight, then subtract. For 9:15 to 17:45, type "17h 45m - 9h 15m" to get 8 Hours 30 Minutes. For an overnight span, add 24h to the end time. This is pure duration math, so it never uses dates, the clock, or now.

Add the clip lengths with + signs, like "22m 30s + 45s + 1m 15s", then pick Minute Second to read 24 Minutes 30 Seconds. Seconds and milliseconds are both supported, so "3m 12s 500ms + 47s" works too. Handy for stacking podcast segments, tracks, or render times.