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UnitChart

Time Converter

Convert seconds, minutes, hours, days, weeks, months and years.

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Check this before you rely on it. This converter is provided free and without warranty, and its results are not professional advice.

Note. Months and years are not fixed lengths. This converter uses the average Gregorian year of 365.2425 days and the average month of one twelfth of that.

Popular time conversions

minutes to hourshours to minutesseconds to minutesdays to hours

Time unit reference chart

What one of each unit is worth in seconds, the base unit used for every conversion in this category.

Time units expressed in seconds
UnitSymbol1 unit in s
secondss1 s
minutesmin60 s
hoursh3,600 s
daysd86,400 s
weekswk604,800 s
monthsmo2,629,746 s
yearsyr31,556,952 s
millisecondsms0.001 s
microsecondsµs0.000001 s
nanosecondsns1e-9 s
fortnightsfn1,209,600 s
decadesdec315,569,520 s
centuriesc3,155,695,200 s

Time units explained

Seconds (s)

The second is the SI base unit of time, defined by 9,192,631,770 periods of the radiation of the caesium-133 atom.

Minutes (min)

A minute is exactly 60 seconds. The sixty-fold division of the hour comes from Babylonian sexagesimal arithmetic.

Hours (h)

An hour is 60 minutes, or exactly 3,600 seconds — one twenty-fourth of a mean solar day.

Days (d)

A day is exactly 86,400 seconds by definition. The Earth’s actual rotation drifts slightly from this, which is what leap seconds correct.

Weeks (wk)

A week is 7 days, or exactly 604,800 seconds. Unlike the month and the year it has no astronomical basis.

Months (mo)

The average Gregorian month is 30.436875 days — one twelfth of the 365.2425-day mean year.

Years (yr)

The mean Gregorian year is 365.2425 days, which accounts for the leap-year rules.

Milliseconds (ms)

A millisecond is one thousandth of a second. Network latency, camera shutter speeds and audio buffers are all measured in milliseconds.

Frequently asked questions

What is the base unit of time?

This converter routes every time conversion through the second. Converting from one unit to another means converting to seconds first and then out again, which keeps every pair consistent with every other pair.

How accurate are these time conversions?

Results are shown to 10 significant digits using exact defined factors wherever a unit has one. Months and years are not fixed lengths. This converter uses the average Gregorian year of 365.2425 days and the average month of one twelfth of that.

All time conversions

Every time conversion page on this site, 92 in total.