About the Time Converter
The Time Converter changes a length of time from one unit into another: hours to minutes, days to hours, seconds to days, weeks to months. Type a number, pick the two units, and the result appears instantly, along with the same duration in all 15 units.
It comes in handy for timesheets and billing in decimal hours, project plans in weeks and months, cooking and workout timers, video and audio lengths, and programming, where timeouts and delays are often written in milliseconds or even nanoseconds.
Seconds, minutes, hours, days and weeks have exact sizes. Months and years do not, so the tool uses the average length in the Gregorian calendar: a year of 365.2425 days and a month of one twelfth of that. Everything runs in your browser.
How to use it
- Enter a durationType the number in the From box. Decimals work, such as 1.5 hours or 0.25 days.
- Pick the unitsChoose the From and To units, or click a common pair like Hours → Minutes or Days → Hours.
- Swap if neededThe swap button reverses the direction, so 90 minutes becomes a question about hours.
- Read the factorThe line under the boxes shows what to multiply by, such as "Hours to minutes: multiply by 60".
- See every unit and copyThe list below shows the duration in all 15 units. Pick the precision and copy any value.
Key features
15 time units
Nanoseconds, microseconds, milliseconds, seconds, minutes, hours, days, weeks, fortnights, months, quarters, years, decades, centuries and millennia.
Honest calendar averages
Months, quarters and years are labeled as averages: 30.436875, 91.310625 and 365.2425 days, the long-run lengths of the Gregorian calendar.
All units at once
One value fills the whole list, so you can see a deadline in days, weeks and months at the same time.
Tiny and huge values
Nanoseconds and millennia sit in the same list. Very small and very large results switch to scientific notation.
Precision you choose
4, 6, 10 or 15 significant digits, and copy buttons that give plain numbers for spreadsheets.
Private by design
No sign-up and no upload. Everything is calculated on your device.
Examples
Decimal hours for timesheets
| From | To | On the clock |
|---|---|---|
| 1.5 hours | 90 minutes | 1 h 30 min |
| 0.75 hours | 45 minutes | 45 min |
| 7.75 hours | 465 minutes | 7 h 45 min |
| 40 hours | 1.666666667 days | 1 day 16 h |
Payroll systems often want decimal hours. To read one as hours and minutes, keep the whole number and convert only the decimal part: 0.75 hours is 45 minutes, so 7.75 hours is 7 hours 45 minutes, not 7 hours 75 minutes.
Days, weeks and months
| From | To |
|---|---|
| 1 week | 168 hours, 10,080 minutes |
| 100 days | 14.28571429 weeks |
| 1 month (average) | 30.436875 days, 4.348125 weeks |
| 9 months (average) | 39.133125 weeks |
| 1 quarter (average) | 91.310625 days |
No real month is 30.436875 days long. That figure is the average over the 400-year Gregorian cycle, which makes it right for long-run planning but not for counting days to a specific date. For that, use the Date Difference Calculator.
Years and big numbers
| From | To |
|---|---|
| 1 year (average) | 365.2425 days, 8,765.82 hours, 31,556,952 seconds |
| 365 days | 0.9993360576 years |
| 1,000,000 seconds | 11.57407407 days |
| 1,000,000,000 seconds | 31.68873851 years |
| 10,000 hours | 1.140794586 years |
A million seconds is under 12 days, but a billion seconds is almost 32 years. And the famous "10,000 hours" of practice is about 1.14 years of nonstop time, or roughly five years at 40 hours a week.
Milliseconds and smaller
One frame of a 60 fps video lasts 1 ÷ 60 of a second, which you can enter as 16.66666667 milliseconds to get 0.01666666667 seconds. A 500 ms timeout in code is 0.5 seconds, 1 millisecond is 1,000,000 nanoseconds, and 1 nanosecond is 1 × 10⁻⁹ seconds.
Tips
- Split decimal hours before you read them: the part after the point times 60 gives the minutes. 2.2 hours is 2 hours 12 minutes.
- Use weeks, not months, for project estimates when you can. Weeks have a fixed length; months do not.
- To check how long a video or podcast is in hours, enter its length in minutes and read the hours line in the list.
- For a specific span between two calendar dates, the Date Difference Calculator counts real month lengths and leap years.
- Converting a clock time between cities is a time zone question, not a unit question. The Timestamp Converter shows one moment in different zones.
Common mistakes and limits
- Reading 1.5 hours as 1 hour 50 minutesDecimal hours are fractions of 60. 1.5 hours is 1 hour 30 minutes, and 1.50 is the same number.
- Treating "months" as calendar monthsThe month here is an average of 30.436875 days. February has 28 or 29 days and July 31, so a real month can differ by up to two and a half days.
- Expecting 365 days in a yearThe tool uses 365.2425 days, which includes leap years on average. Enter 365 days if you need a common year.
- Looking for time zones hereThis tool converts durations. 3:00 PM in New York to London time is a different question, answered by the Timestamp Converter.
- Counting leap secondsEvery day here is exactly 86,400 seconds. Leap seconds, which have been added to UTC now and then, are not included, which is also how most computer clocks work.