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
Conversion factors use the exact defined values given in NIST Special Publication 811 and the BIPM SI Brochure wherever such a definition exists (for example 1 lb = 0.45359237 kg, 1 in = 2.54 cm, 1 US gal = 3.785411784 L, g₀ = 9.80665 m/s²); derived factors are computed from those definitions rather than copied as rounded figures. Results are calculated in double-precision floating point and shown to 10 significant digits, so the last digit can differ by one unit of rounding. The rounded figures in the text and tables above are for reading convenience. Month and year are conventions: the year is the Julian year (365.25 days = 31,557,600 s) and the month is one twelfth of it (30.4375 days = 2,629,800 s).
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 |
| 2,629,800 s | 43,830 min | 730.5 h | One month (avg) |
| 31,557,600 s | 525,960 min | 8,766 h | One year |