Time Unit Converter
Convert between seconds, minutes, hours, days, weeks, months and years.
How to use this calculator
- 1Enter the value you want to convert.
- 2Pick the unit you are converting from and the one you want.
- 3The table below shows the same value in every other supported unit.
How the calculation works
result = (value × factor(from) ) / factor(to)- factor
- How many seconds one unit represents
Every value is converted to seconds first, then out to the target unit. This means n units need n factors rather than n² conversion pairs.
Months and years use the Gregorian mean: the year is 365.2425 days, averaging the leap-year rule over a 400-year cycle, and a month is exactly one twelfth of that. No calendar month is actually this length.
For anything requiring real calendar arithmetic — how many days between two dates, or what date is 3 months from now — use the date calculators instead. Averaged months give the wrong answer for specific dates.
Worked example
1 day to hour
- 1.One day is 86,400 seconds, so 1 d is 86,400 seconds.
- 2.One hour is 3,600 seconds, so divide: 86,400 ÷ 3,600 = 24.
- 3.Put another way, 1 d = 24 h.
Result: 24 h
What this assumes, and where it stops
Assumptions
- Conversion factors follow the internationally agreed definitions of each unit.
Limitations
- Month and year conversions are averages. Real months vary from 28 to 31 days and real years from 365 to 366, so converting a specific date range this way will be wrong by up to a few days.
Common questions
Why is a year 365.2425 days rather than 365.25?
Because the Gregorian calendar skips three leap years every four centuries — years divisible by 100 are not leap years unless also divisible by 400. That correction brings the average from the Julian 365.25 down to 365.2425, which tracks the actual solar year far more closely.
Can I use this to work out days between two dates?
Not accurately. This converter uses average month and year lengths, so it cannot know that February is short or that a particular year has a leap day. Use the Date Difference Calculator, which does real calendar arithmetic.
Formula and content last reviewed on .
Results are estimates for information only, not professional advice.
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