Time Converter

Convert seconds, minutes, hours, days, weeks, months and years, down to nanoseconds.

Decimals, fractions (3 1/2) and e-notation (1.5e6) all work.
Common Conversions
Significant Digits
Result
Formula
Reverse
Exact?

In Every Unit

UnitValue

Saved Conversions

Conversions you add are saved in this browser.

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How to Convert Time Units

Seconds, minutes, hours, days and weeks convert exactly. Months and years vary in length, so this page uses the average Gregorian year of 365.2425 days and a month of one-twelfth of that (30.436875 days).

minutes = hours × 60   seconds = hours × 3,600   days = weeks × 7

Worked Example

Common Conversions

FromEquals
1 h60 min
1 min60 s
1 d24 h
1 wk7 d
1 yr365.2425 d
1 s1,000 ms
1 mo30.43688 d

Unit Definitions

UnitEqualsExact?
Nanoseconds (ns)1 × 10⁻⁹ sExact
Microseconds (µs)0.000001 sExact
Milliseconds (ms)0.001 sExact
Seconds (s)1 sExact
Minutes (min)60 sExact
Hours (h)3,600 sExact
Days (d)86,400 sExact
Weeks (wk)604,800 sExact
Months (average) (mo)2,629,746 sAverage
Years (average Gregorian) (yr)31,556,952 sAverage
Years (365 days) (365-day yr)31,536,000 sExact
Decades (average) (decade)315,569,520 sAverage
Centuries (average) (century)3,155,695,200 sAverage

Factors follow NIST Special Publication 811, Appendix B. "Exact" means the unit is defined as that value; results are rounded only for display.

Tips

For a specific span between two dates, use a date difference calculator instead, since real months run 28 to 31 days. Decimal hours: 2.5 hours is 2 hours 30 minutes.