Time Calculator
Convert a duration between nanoseconds, microseconds, milliseconds, seconds, minutes, hours, days, weeks, months, years, decades, centuries and millennia. Months and years use the average Gregorian calendar (365.2425 days per year), so long spans such as 1 billion seconds convert consistently.
What does the Time Calculator do?
It converts a length of time into 14 units, from nanoseconds up to millennia. Enter a duration in any unit, for example a timeout in milliseconds or a project length in weeks, and every other unit is shown at once. Calculations are done in your browser with high-precision decimals.
How to use
- Type a number in a row, for example 1000000 in Second. The other rows show ≈ 11.5741 days, ≈ 277.778 hours, and so on.
- Change rounding digits to see more or fewer decimals.
- Enable Description to read how each unit is defined (especially month and year), Ratio to compare each unit with the top row, and Separators for thousands separators.
- Reorder units by dragging the handle; the top row is the (base unit) for the ratios.
- Press Up / Down in a field to add or subtract one of that unit, e.g. one day at a time.
Units and definitions
| Unit | Definition |
|---|---|
| Nanosecond (ns) | 10⁻⁹ s |
| Microsecond (μs) | 10⁻⁶ s |
| Millisecond (ms) | 0.001 s |
| Second (s) | SI base unit of time |
| Minute / Hour | 60 s / 3,600 s |
| Day | 24 h = 86,400 s |
| Week / Fortnight | 7 days / 14 days |
| Month | 1/12 year = 30.436875 days |
| Year | 365.2425 days = 31,556,952 s |
| Decade / Century / Millennium | 10 / 100 / 1,000 years |
Conversion examples
- 1 h = 3,600,000 ms
- 1 week = 604,800 s
- 1,000,000 s ≈ 11.5741 days
- 1,000,000,000 s ≈ 31.6887 years
Features
- 14 time units from nanoseconds to millennia
- Enter a value in any row; the rest update immediately
- Consistent average Gregorian month and year
- Rounding control, separators, ratios and unit descriptions
- Unit order, last value and options are remembered in this browser
FAQ
Why is a month 30.436875 days?
Calendar months vary from 28 to 31 days, so a fixed factor is needed for conversion. The tool uses the average Gregorian year of 365.2425 days divided by 12. For the exact difference between two calendar dates, use ToolPocket's time difference tool instead.
Can it show a result like "1 d 2 h 3 min"?
No. Each row shows the whole duration in a single unit with decimals. It does not split a duration into mixed units or add and subtract times.
Does it convert Unix timestamps?
No. This tool converts durations. To turn Unix timestamps into dates, use ToolPocket's Unix timestamp tool.