Seconds to Minutes

A result such as 4.25 minutes is 4 minutes 15 seconds, not 4:25, because the fraction is of 60. To write seconds as mm:ss, divide by 60, keep the whole number as minutes and put the remainder as seconds: 245 s is 4 remainder 5, so 4:05.

Video sites use raw seconds in links; a timestamp parameter of 125 jumps to 2:05. Editing software and subtitle files run the other way, printing hh:mm:ss with frames or milliseconds. Video length also sets file size, since every second costs the same bitrate; a 90-second clip at 1 MB per second is 90 MB, which is why compress video to 10 MB mainly lowers the bitrate.

Runners think in seconds per kilometer or mile. A pace of 300 seconds per kilometer is 5:00 per km, which equals 12 km/h. Over a marathon of 42.195 km that pace adds up to 12,659 seconds, about 3 hours 31 minutes. Lap timers and the stopwatch record seconds and hundredths, and converting the total to minutes makes splits easier to compare.

Swimmers and track athletes quote times as m:ss.hh, so 1:52.40 means 112.4 seconds. Adding several splits is easiest in seconds first, then converting back.

A day is 24 × 60 × 60 = 86,400 seconds and a week is 604,800. Because Earth's rotation varies slightly, 27 leap seconds were added to UTC between 1972 and 2016 so clocks stayed in step with the sun; in 2022 the General Conference on Weights and Measures voted to stop adding them by 2035. Unix time ignores leap seconds and treats every day as 86,400 seconds. For larger spans, go on to minutes to hours.