Time Converter
Convert any length of time between milliseconds, seconds, minutes, hours, days, weeks, months and years.
All units
🔒 Runs entirely in your browser. Nothing you enter is sent to a server.
Time is one of the few measurements that doesn’t use a base-ten system. It mixes factors of 60, 24, 7 and the uneven lengths of months and years. That makes quick mental conversions surprisingly error-prone, especially across several steps such as turning 150,000 seconds into days. This tool does every step at once and shows the result in every unit.
How to use the time converter
- Enter a duration in Value. Decimals such as 1.5 hours are fine.
- Choose the unit you have and the unit you want.
- Read the result, or check the table for the same duration in every unit.
Time units and how they are defined
| Unit | In seconds | Notes |
|---|---|---|
| 1 millisecond | 0.001 | Common in programming and benchmarks |
| 1 minute | 60 | |
| 1 hour | 3,600 | 60 minutes |
| 1 day | 86,400 | 24 hours |
| 1 week | 604,800 | 7 days |
| 1 month (average) | 2,629,746 | 30.436875 days |
| 1 year (average) | 31,556,952 | 365.2425 days, the Gregorian average |
Worked examples
- 90 minutes is 1.5 hours.
- 10,000 seconds is about 2.78 hours, or 2 hours, 46 minutes and 40 seconds.
- A 40-hour work week is 2,400 minutes.
- 1 million seconds is about 11.6 days. 1 billion seconds is about 31.7 years.
Practical uses
- Timesheets and payroll: convert minutes worked into decimal hours, since 7 h 30 min is 7.5 h.
- Programming: many APIs expect timeouts and intervals in milliseconds, while cache settings use seconds. 5 minutes is 300 s, or 300,000 ms.
- Project planning: turn a task estimate in hours into working days. Divide by your hours per day, not 24.
- Fitness and cooking: convert total seconds from a stopwatch into minutes and seconds.
Frequently asked questions
How many seconds are in a day?
86,400 seconds, which is 24 hours × 60 minutes × 60 seconds. A week has 604,800 seconds.
How long is a month in this converter?
The converter uses an average Gregorian month of 30.436875 days, which is 365.2425 ÷ 12. Real calendar months vary from 28 to 31 days, so use a date calculator when you need an exact span between two dates.
How do I convert decimal hours to hours and minutes?
Keep the whole number as hours and multiply the decimal part by 60 to get minutes. For example, 2.75 hours is 2 hours plus 0.75 × 60 = 45 minutes.