What is this converter?
Converts a duration between milliseconds, seconds, minutes, hours, days, and weeks. All conversions pass through the second, the SI base unit of time.
Use it when:
- You need a timeout or duration expressed in different units.
- You are converting a processing time between seconds and hours.
- You want a long duration restated in days or weeks.
Intended for: Developers, planners, and anyone restating a duration in more convenient units.
How is this calculated?
- Each supported unit is defined by a fixed conversion factor relative to one base unit for the quantity (for example, the metre for length).
- The value you enter is first converted from the source unit into that base unit by multiplying by the source unit's factor.
- The base value is then converted into the target unit by dividing by the target unit's factor.
- Because both factors are exact constants, the conversion is a single deterministic multiplication and division — the same input always produces the same output.
Example
Converting 90 minutes to hours.
- 1 minute is 60 seconds; 1 hour is 3,600 seconds.
- 90 × 60 ÷ 3,600 = 1.5.
Result: 90 minutes = 1.5 hours.
Frequently asked questions
Why are months and years not offered?
Because they have no fixed length: months vary from 28 to 31 days and years from 365 to 366. Converting them by a fixed factor would be wrong. For calendar arithmetic, use the date difference calculator instead.
Does this account for leap seconds or daylight saving?
No. It converts abstract durations by fixed factors. A calendar day during a daylight-saving change may be 23 or 25 hours long; that is calendar arithmetic, not unit conversion.
Assumptions
What this converter takes as given:
- Conversion factors are the internationally standardised definitions of each unit, not regional or historical variants.
- The value you enter is treated as an exact quantity — no measurement uncertainty is carried through the conversion.
- Results are rounded only for display; the underlying arithmetic uses full precision.
Limitations
What this converter cannot know or does not model:
- The converter does not know the precision of your original measurement, so it cannot report significant figures for you.
- Units that share a name but differ by region or era (for example, different definitions of a gallon or a ton) are offered only in the variants listed in the unit menu.
- Very large or very small magnitudes are subject to the limits of double-precision floating-point arithmetic.
- Months and years are excluded because their lengths are not fixed.
- Calendar effects — leap seconds, daylight saving, and time zones — are outside a unit conversion.