Time Converter
Seconds, minutes, hours, days and years.
Convert
Result
60 min
1 hour in minute
1 h = 60 min
Time Conversion Math Formula
Time is the odd one out because it does not run on powers of ten. Seconds, minutes and hours come from the base-60 counting the Babylonians used, so the factors are 60, 60 and 24 instead of 10, 100 and 1,000. The method is the same, though: multiply by a fraction that equals 1. Sixty seconds and one minute are the same duration, so (60 s ÷ 1 min) is just 1.
The converter goes through seconds. Seconds, minutes, hours, days and weeks are exact. Months and years are not fixed in the real calendar, so the tool uses averages: a year of 365.2425 days, the mean length of a Gregorian calendar year, and a month of one twelfth of that, 30.436875 days.
The formula
value in B = value in A × (seconds per A) ÷ (seconds per B)1 min = 60 s, 1 h = 60 min = 3,600 s, 1 d = 24 h = 86,400 s1 wk = 7 d = 604,800 s, 1 yr (average) = 365.2425 d = 31,556,952 s
Worked example 1: 3.5 hours, in minutes
3.5 h × (60 min ÷ 1 h)Answer: 210 min
Worked example 2: 10,000 seconds, in hours
10,000 s × (1 h ÷ 3,600 s)Answer: 2.77778 h
That 2.77778 hours is a decimal. For the clock form, keep the 2 whole hours and convert the rest: 0.77778 h × 60 = 46.667 min. Keep 46 minutes, and 0.667 min × 60 = 40 s. So 10,000 s is 2 h 46 min 40 s.
Worked example 3: One billion seconds, in years
1,000,000,000 s × (1 yr ÷ 31,556,952 s)Answer: 31.6887 yr
A person who is about 31 years and 8 months old has lived roughly one billion seconds.
Worked example 4: One year, in hours
365.2425 d × (24 h ÷ 1 d)Answer: 8,765.82 h
A plain 365-day year has 8,760 hours and a leap year has 8,784. The average sits between them.
Common mistakes to avoid
- Treating decimal hours as hours and minutes. 1.5 hours is 1 hour 30 minutes, not 1:50. Time is base 60, so a decimal part means a fraction of 60 minutes: 0.25 h is 15 min and 0.75 h is 45 min. To convert a decimal part, multiply it by 60.
- Assuming every month is the same length. Calendar months run from 28 to 31 days. The tool's month is the average, 30.4369 days, which is right for long-run estimates and wrong for a specific date range. For the days between two dates, count the actual days.
- Forgetting leap years. A flat 365 days is wrong over the long run. The Gregorian calendar adds a leap day in most years divisible by 4, except century years not divisible by 400, which is where the 365.2425-day average comes from.
About time units
The second is the SI base unit of time. Since 1967 it has been defined from caesium-133 atoms: exactly 9,192,631,770 periods of the radiation tied to a particular transition in the atom.
Everything shorter than a second uses the metric prefixes: milliseconds, microseconds, nanoseconds. Everything longer uses the old Babylonian and calendar factors: 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, 7 days in a week. A year follows the Earth's orbit and is not a whole number of days, which is why calendars need leap years.
- Millisecond (ms)1 ms = 0.001 sOne thousandth of a second. Camera shutters, network pings and reaction times are quoted in milliseconds.
- Second (s)The SI base unit, fixed by 9,192,631,770 caesium periods.
- Minute (min)1 min = 60 sSixty seconds.
- Hour (h)1 h = 3,600 sSixty minutes.
- Day (d)1 d = 86,400 sTwenty-four hours, the length of a civil day.
- Week (wk)1 wk = 604,800 sSeven days.
- Month (average) (mo)1 mo = 2,629,746 sThe average Gregorian month, 30.436875 days. Real months vary from 28 to 31 days.
- Year (average) (yr)1 yr = 31,556,952 sThe average Gregorian year, 365.2425 days.
Time conversion table
| Value | s | min | h | d |
|---|---|---|---|---|
| 1 min | 60 | 1 | 0.0166667 | 0.000694444 |
| 1 h | 3,600 | 60 | 1 | 0.0416667 |
| 1 d | 86,400 | 1,440 | 24 | 1 |
| 1 wk | 604,800 | 10,080 | 168 | 7 |
| 1 mo | 2,629,750 | 43,829.1 | 730.485 | 30.4369 |
| 1 yr | 31,557,000 | 525,949 | 8,765.82 | 365.243 |
Time converter FAQ
How many seconds are in a day?
86,400: 24 hours × 60 minutes × 60 seconds. A week has 604,800 seconds and an average year has about 31.56 million.
How many hours are in a year?
8,760 in a normal 365-day year, 8,784 in a leap year, and 8,765.82 on average over the Gregorian cycle (365.2425 × 24).
How do I convert decimal hours to hours and minutes?
Keep the whole number as hours and multiply the decimal part by 60 for the minutes. 2.4 hours is 2 hours and 0.4 × 60 = 24 minutes. A timesheet that says 7.75 hours means 7 h 45 min.
How many weeks are in a year?
52.1775 on average (365.2425 ÷ 7), which is 52 weeks and about 1.24 days. That leftover day or so is why a given date moves to a different weekday each year.
Why does the converter use an average month?
Months differ: February has 28 or 29 days and the others have 30 or 31. A fixed average of 30.4369 days is the only way to compare a month with a number of days in one formula. If the exact number of days between two dates matters, count them on a calendar.
How do I convert milliseconds to seconds?
Divide by 1,000. 2,500 ms is 2.5 s. To go back, multiply by 1,000: a lap of 1.25 s is 1,250 ms.