Free Time Converter
Convert time units instantly — seconds, minutes, hours, days, weeks, months, years, milliseconds, microseconds. Free, symmetrical, no sign-up.
Exact Conversion Formula & Multipliers
The base SI unit, the second, has been defined since 1967 as exactly 9,192,631,770 cycles of radiation from a cesium-133 atomic transition — not by any celestial observation. From that fixed second, 1 minute = 60 s, 1 hour = 3,600 s, and 1 day = 86,400 s are simple integer multiples, though the actual mean solar day is not perfectly constant, which is why leap seconds are occasionally inserted into civil timekeeping.
Practical Real-World Scenarios
- Global scheduling: coordinating meetings across time zones requires converting hours and minutes while also accounting for date-line shifts and daylight saving offsets.
- Scientific and engineering timing: physics experiments and computing systems measure durations in seconds or milliseconds, converting to human-readable hours and minutes only for reporting.
- Media and broadcasting: video and audio duration is tracked in frames, seconds, and timecodes that must be reconciled across formats with different frame rates.
Historical & Technical Background
Dividing the day into 24 hours and each hour into 60 minutes traces back to ancient Egyptian and Babylonian sexagesimal (base-60) counting systems, chosen for their high divisibility. The definition of the second itself has evolved dramatically — from a fraction of the mean solar day, to a fraction of a specific year (1956), to today's atomic-clock definition — because astronomical time turned out to be too irregular for the precision modern science and technology require.
Precision & Accuracy Statement
Every conversion factor used on this page is checked against internationally recognized reference standards — the BIPM cesium-133 definition of the second (SI Brochure) and NIST time standards — rather than approximated or rounded for display. Where a constant is fixed by international definition (such as 1 inch = 2.54 cm, or standard gravity = 9.80665 m/s²), we use the exact defined value. Where a figure is a practical industry convention rather than a physical constant, that distinction is stated explicitly above so results are never presented with false precision.
How This Converter Works
Time spans everything from nanoseconds in computing to years in planning. Our converter handles 10 time units from nanoseconds to years simultaneously, useful for everything from coding to project management.
Common Conversions
| Seconds | Minutes | Hours | Context |
|---|---|---|---|
| 60 s | 1 min | 0.0167 h | One minute |
| 3,600 s | 60 min | 1 h | One hour |
| 86,400 s | 1,440 min | 24 h | One day |
| 604,800 s | 10,080 min | 168 h | One week |
| 2,628,000 s | 43,800 min | 730 h | One month (avg) |
| 31,557,600 s | 525,960 min | 8,766 h | One year |