Time Calculatorby Cardamon

Add Up Video and Audio Lengths (mm:ss and Milliseconds)

Dmitrii Kargashin By Dmitrii Kargashin · Updated June 2026

To total video or audio lengths, enter each clip as minutes and seconds and add them: "2m 45s + 3m 12s + 1m 58s" returns 7 Minutes 55 Seconds in the Minute Second format. The seconds roll into minutes automatically, and minutes roll into hours when you pick the Hour Minute Second format.

Editors, podcasters, and musicians stack clip and track lengths constantly, and the math is annoying because 45s plus 30s is not 75, it is 1:15. This calculator carries seconds into minutes and minutes into hours for you. Enter each length as a number plus a unit, add them, and read the total in whichever mm:ss or h:mm:ss format you need. It also works in milliseconds, which most time calculators drop. The web version is free and ad-supported, running the same engine as the mobile apps.

Step by step

  1. Type each clip as minutes and seconds

    Write a length as a number and a unit with no colon: a 2:45 clip is "2m 45s", a 12-second sting is "12s". Use "m" for minutes and "s" for seconds. A bare number is only allowed as a multiplier, so always attach a unit to each length.

  2. Add them with the plus sign

    Chain the clips with +, for example "2m 45s + 3m 12s + 1m 58s". The engine sums everything in the background and carries 60 seconds up into a minute, so you never have to fix overflowing seconds by hand.

  3. Pick Minute Second for short reels

    Set the result format to Minute Second to read totals as whole minutes and seconds, like 7 Minutes 55 Seconds. This is the format you want for a single reel, a song, or a short clip stack that stays under an hour.

  4. Switch to Hour Minute Second once you cross an hour

    For a full playlist or episode, choose Hour Minute Second. A four-clip set like "18m 30s + 22m 15s + 12m 45s + 14m 50s" reads 1 Hour 8 Minutes 20 Seconds, with the minutes rolling cleanly into one hour.

  5. Work in milliseconds for audio and frames

    Add the ms unit for sub-second precision most calculators skip. Use "1s - 250ms" to find a 750 ms gap, or multiply a frame duration: "41ms * 30" with the Hour Minute Second MSecond format gives 0 Hours 0 Minutes 1 Second 230 MSeconds. Pick a format ending in MSecond to keep the millisecond digits.

Worked examples

2m 45s + 3m 12s + 1m 58s=7 Minutes 55 Seconds

Total three short clips for a reel; seconds carry into minutes automatically.

18m 30s + 22m 15s + 12m 45s + 14m 50s=1 Hour 8 Minutes 20 Seconds

Sum a playlist of segments that crosses the one-hour mark.

1s - 250ms=750 MSeconds

Find the millisecond gap left after trimming a quarter-second from a one-second cue.

41ms * 30=1 Second 230 MSeconds

Multiply one frame at 41 ms by 30 frames to get the clip length to the millisecond.

Try it yourself

Show result as
Try

Type hours, minutes, days, weeks, months, years, or seconds, as full words or shorthand (h m d w), with + - * /. Pick how the answer reads with Show result as up top. It all runs in your browser. Drag the card’s right edge to make it wider.

Common questions

How do I total clip lengths in mm:ss?

Type each clip as minutes and seconds with a unit, like "3m 20s", join them with +, and set the result format to Minute Second. The calculator carries every 60 seconds into a minute, so "3m 20s + 2m 50s" returns 6 Minutes 10 Seconds rather than 5:70.

What if my total goes over an hour?

Switch the result format to Hour Minute Second. The same sum then rolls 60 minutes into an hour, so a long playlist shows as something like 1 Hour 8 Minutes 20 Seconds instead of 68 minutes.

Can it handle milliseconds?

Yes. Use the ms unit, which many time calculators lack. You can compute "1s - 250ms" to get 750 MSeconds, or multiply a frame or sample duration. Pick any result format ending in MSecond to keep the millisecond digits visible.

Why do I have to add a unit to every number?

Each value needs a unit so the engine knows whether 3 means minutes, seconds, or milliseconds. A bare number is only valid as a multiplier or divisor, as in "41ms * 30" or "6m / 2". "2 + 2" alone is not a valid time expression.

Does this know the actual clock time or release date?

No. It works with durations only. It adds, subtracts, multiplies, and divides lengths of time. It does not track wall-clock time, calendar dates, or the current moment, so it cannot tell you when a render will finish in real time.

For video editors, podcasters, and musicians totalling clip runtimes and track lengths down to the millisecond.

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