Time Unit Converter
( ms, s, min, h, d, yr & more )
Convert between milliseconds, seconds, minutes, hours, days, weeks, months, years, decades, centuries and more. Enter any value, get instant results.
All time units relative to 1 second (s). Year = 365 days.
| Unit Name | Symbol | Value in Seconds | Common Usage |
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Understanding Time Measurement Units
Time is a fundamental dimension. The SI base unit is the second (s). From it, we derive larger units: minutes, hours, days, and years. The relationships are well‑known, but some (like months and years) have variations (leap years, month lengths).
Standard Conversions
1 minute = 60 s, 1 hour = 60 min = 3600 s, 1 day = 24 h = 86,400 s, 1 week = 7 d = 604,800 s. For longer periods: 1 common year = 365 d = 31,536,000 s, 1 decade = 10 yr, 1 century = 100 yr, 1 millennium = 1000 yr. Months vary, but a typical month is 1/12 year ≈ 30.44 days.
Leap Years & Calendar Nuances
The Gregorian calendar adds a leap day every 4 years (except centuries not divisible by 400). This tool uses a common year of 365 days for simplicity. For precise historical or astronomical calculations, specialized calendars should be used.
Where These Units Are Used
- Milliseconds (ms) – computer processing, reaction times
- Seconds (s) – everyday timing, science
- Minutes (min) / Hours (h) – scheduling, travel
- Days (d) / Weeks (wk) – planning, work cycles
- Months (mo) / Years (yr) – age, finance, history
- Decades / Centuries – historical periods, long‑term trends
Browse all 90 dedicated conversion pages, organized by unit.
