Time Unit Converter

Convert time durations between nanoseconds, milliseconds, seconds, minutes, hours, days, weeks, months, years, decades and centuries.

How to use the time Unit Converter

  1. Enter the value.
  2. Choose the from from the list.
  3. Choose the to from the list.
  4. The result updates instantly as you type. There is no button to press.
  5. Use Copy result to copy the figures, or Copy link to share a link that reopens the time Unit Converter with the same inputs.

How it works

Time is the one quantity where even the metric system isn't decimal. Seconds group into 60-second minutes and 60-minute hours, inherited from Babylonian base-60 counting, then 24-hour days and 7-day weeks. That makes conversions by hand error-prone, so this converter turns any duration into every other unit and also breaks it down into days, hours, minutes and seconds.

Days, hours, minutes and shorter units convert exactly. Months and years don't have fixed lengths, so they need an average. This tool uses the Gregorian year of 365.2425 days, the average over the 400-year leap-year cycle, and a month of one twelfth of that, 30.436875 days. Those averages are right for long durations, such as "how many seconds are in 30 years", but a specific calendar month can be anywhere from 28 to 31 days. For gaps between real dates, use the date difference calculator.

The small units are useful in computing and science: a millisecond is a thousandth of a second (typical network latency is 10–100 ms), a microsecond a millionth, and a nanosecond a billionth, roughly the time light takes to travel 30 cm.

Formula

1 min = 60 s · 1 h = 3,600 s · 1 day = 86,400 s 1 week = 604,800 s 1 year (avg) = 365.2425 days = 31,556,952 s 1 month (avg) = 1/12 year = 2,629,746 s

Example

90 minutes ÷ 60 = 1.5 hours, or 1 h 30 min. A million seconds is 11 days, 13 hours, 46 minutes and 40 seconds, while a billion seconds is about 31.7 years. A 40-hour working week is 2,400 minutes or 144,000 seconds.

Frequently asked questions

How many seconds are in a year?

31,536,000 in a 365-day year, 31,622,400 in a leap year, and 31,556,952 in an average Gregorian year of 365.2425 days, which this converter uses.

How many weeks are in a year?

52 weeks and 1 day, or 52 weeks and 2 days in a leap year. On average, a year is about 52.18 weeks.

How do I convert decimal hours to hours and minutes?

Multiply the decimal part by 60. 2.75 hours = 2 hours + 0.75 × 60 = 2 hours 45 minutes. The 'broken down' line does this for you.