Time unit converter
Convert seconds, minutes, hours, days, weeks, months, years and nanoseconds, using the true 365.2425-day Gregorian year average.
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1 min = 0.0166666666667 h
Automatic formatting keeps up to 12 significant digits and switches to scientific notation only for numbers past 10¹⁸ or below 10⁻⁹. You can paste values with thousands separators, and fractions such as 3/4 or 1 1/2 are understood too.
h = min ÷ 60
Your value: 1 ÷ 60 = 0.0166666666667 h
| min | h |
|---|---|
| 1 | 0.0166666666667 |
| 2 | 0.0333333333333 |
| 5 | 0.0833333333333 |
| 10 | 0.166666666667 |
| 15 | 0.25 |
| 30 | 0.5 |
| 45 | 0.75 |
| 60 | 1 |
| 90 | 1.5 |
| 120 | 2 |
| 365 | 6.08333333333 |
| 1,000 | 16.6666666667 |
| h | min |
|---|---|
| 1 | 60 |
| 2 | 120 |
| 5 | 300 |
| 10 | 600 |
| 15 | 900 |
| 30 | 1,800 |
| 45 | 2,700 |
| 60 | 3,600 |
| 90 | 5,400 |
| 120 | 7,200 |
| 365 | 21,900 |
| 1,000 | 60,000 |
| Unit | Symbol | Value in s | Notes |
|---|---|---|---|
| NanosecondSub-second | ns | 1 ns = 0.000000001 s | — |
| MicrosecondSub-second | µs | 1 µs = 0.000001 s | — |
| MillisecondSub-second | ms | 1 ms = 0.001 s | — |
| SecondCommon | s | 1 s = 1 s | SI base unit of time. |
| MinuteCommon | min | 1 min = 60 s | — |
| HourCommon | h | 1 h = 3,600 s | — |
| DayCommon | d | 1 d = 86,400 s | 24 hours exactly (ignoring leap seconds). |
| WeekCommon | wk | 1 wk = 604,800 s | — |
| Month (average)Calendar | mo | 1 mo = 2,629,746 s | One twelfth of a Gregorian year — 30.436875 days. Real months are 28–31 days. |
| Year (Gregorian)Calendar | yr | 1 yr = 31,556,952 s | 365.2425 days, the long-run average once leap years are counted. |
| DecadeCalendar | dec | 1 dec = 315,569,520 s | — |
| CenturyCalendar | cent | 1 cent = 3,155,695,200 s | — |
How to convert a time interval
- Type a duration into either field. This tool converts lengths of time — 90 minutes into hours, 3 days into seconds — not clock times or dates.
- Pick the units. Sub-second units are grouped first for performance work, then the everyday units, then the calendar units.
- If you need the gap between two specific dates, or a deadline, use the date-difference calculator instead: calendar arithmetic has to deal with month lengths and daylight saving, which a unit converter cannot.
The exact ones and the averaged ones
Everything from nanoseconds up to weeks is exact. A minute is 60 seconds, an hour 3,600, a day 86,400 and a week 604,800. Leap seconds occasionally make a real day one second longer, but no ordinary calculation accounts for them and neither does this one.
Months and years are different, because they are calendar constructs rather than fixed intervals. This converter uses the long-run Gregorian averages:
| Unit | Days | Seconds | Why |
|---|---|---|---|
| Year | 365.2425 | 31,556,952 | Leap years every 4 years, skipping 3 in every 400 |
| Month | 30.436875 | 2,629,746 | Exactly one twelfth of that year |
| Week | 7 | 604,800 | Exact |
| Day | 1 | 86,400 | Exact by convention |
So "3 months" here means 91.3 days, not "the next three calendar months", which could be anywhere from 89 to 92 days depending on where you start. For contracts, notice periods and billing cycles, count the actual dates.
Reference: durations you convert often
| Duration | In minutes | In hours | In seconds |
|---|---|---|---|
| 45 minutes | 45 | 0.75 | 2,700 |
| 90 minutes | 90 | 1.5 | 5,400 |
| 1 day | 1,440 | 24 | 86,400 |
| 1 week | 10,080 | 168 | 604,800 |
| 1 working month (160 h) | 9,600 | 160 | 576,000 |
| 1 year | 525,949 | 8,765.8 | 31,556,952 |
Sub-second units and why they matter
Performance work lives below the second. A millisecond is a thousandth, a microsecond a millionth and a nanosecond a billionth. For scale: a modern SSD answers a read request in roughly 100 microseconds, main memory in around 100 nanoseconds, and a single CPU cycle at 3 GHz takes about a third of a nanosecond. Network round trips across an ocean are measured in tens of milliseconds — around 150 ms London to Sydney, which is a hard floor set by the speed of light in fibre, not by any equipment.
When you convert into these units the numbers get long fast, so the automatic formatting keeps twelve significant digits and only switches to scientific notation past 10¹⁸.
Questions
How long is a "month" here?
One twelfth of an average Gregorian year — 30.436875 days. Real calendar months are 28 to 31 days, so use the date-difference calculator when exact dates matter.
Why is a year 365.2425 days and not 365?
Because of leap years. The Gregorian rule adds a day every four years, skips century years, but keeps every fourth century — averaging out to 365.2425 days.
How many seconds are in a day?
86,400, assuming a 24-hour day. Occasional leap seconds make a handful of real days one second longer, but no ordinary calculation accounts for them.
Can I convert milliseconds for performance work?
Yes — nanoseconds, microseconds and milliseconds are all included, and the automatic formatting keeps up to 12 significant digits before switching to scientific notation.