⏱️ Time Converter
Convert milliseconds, seconds, minutes, hours, days, weeks, months, and years.
Enter a value above to see the result
Common Time Conversions
| Input | Unit | Result | Unit |
|---|---|---|---|
| 1 | Hour | 60 | Minute |
| 1 | Day | 24 | Hour |
| 1 | Year | 365.25 | Day |
| 90 | Minute | 1.5 | Hour |
| 1 | Week | 7 | Day |
| 1 | Day | 86400 | Second |
Formula Reference
Exact ratios: 1 min = 60 s • 1 hr = 3,600 s • 1 day = 86,400 s Approximations used here: 1 month ≈ 30.4375 days (Julian) • 1 year ≈ 365.25 days (Julian)
About Time Conversions
Time is the most universally experienced measurement. From milliseconds in computing performance benchmarks to years in historical records, time spans an enormous range of scales. Conversions between seconds, minutes, hours, and days involve exact, fixed ratios and rarely cause confusion. Months and years, however, require careful approximation.
This converter uses the Julian year (365.25 days) and Julian month (approximately 30.4375 days), which average in the leap year cycle. Real calendar months vary from 28 to 31 days, and a real year is 365 or 366 days. For anything requiring calendar precision — scheduling, contracts, legal deadlines — use an actual calendar rather than these averages.
In computing, time precision goes well below the second. Milliseconds (1/1,000 second) are used for web page load times and database queries. Microseconds and nanoseconds matter in hardware design and networking. The second itself is defined with extraordinary precision: since 1967, it has been the duration of exactly 9,192,631,770 periods of radiation from a cesium-133 atom — making it the most accurately measured SI base unit.
Frequently Asked Questions
How many seconds are in a day?
There are exactly 86,400 seconds in a 24-hour day. The calculation: 60 seconds × 60 minutes × 24 hours = 86,400. This figure is widely used in computing, physics, and astronomy.
How many weeks are in a year?
A standard calendar year has 52 complete weeks plus 1 or 2 extra days. The Julian year (365.25 days) used in this converter equals exactly 52.1775 weeks. This is why some years have a 53rd week on certain calendar systems.
Why does this converter use approximate values for months and years?
Calendar months vary from 28 to 31 days, and years alternate between 365 and 366 days. To provide a single useful conversion factor, this tool uses Julian averages: 30.4375 days per month and 365.25 days per year. For exact date arithmetic, use a proper date library or calendar.
How many minutes are in a day?
There are exactly 1,440 minutes in a 24-hour day (60 minutes × 24 hours). That means there are also 1,440,000 milliseconds in a minute of thinking about it differently — and exactly 604,800 minutes in a standard 7-day week.
How is a second officially defined?
Since 1967, the second is defined as exactly 9,192,631,770 oscillation cycles of the radiation emitted by a cesium-133 atom transitioning between two specific energy levels. This atomic definition is so precise that atomic clocks lose less than one second per 300 million years.
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All conversion results are provided for general informational purposes only. Our formulas use internationally recognized conversion factors; however, rounding may affect precision. Do not rely on these results for professional, medical, legal, or engineering decisions without independent verification. Read our full disclaimer.