Convert a duration into seconds, minutes, hours, days, weeks or smaller units without relying on a start date or a timezone.
Enter a decimal duration
Choose the original unit and the result unit. For two and a half hours, enter 2.5 hours: the result is 150 minutes. A decimal such as 1.30 hours means 1 hour plus 0.30 × 60 minutes, or 1 hour 18 minutes; it does not mean 1 hour 30 minutes. Use the Time Calculator for clock-style arithmetic.
Fixed units versus calendar periods
A day in this converter is exactly 24 hours, a week is seven such days, and the two year choices are explicitly fixed at either 365 or 365.25 days. The latter is the Julian year used as a duration unit. Neither choice reads a particular calendar year.
Months are omitted because their length varies. Local calendar days may span a daylight-saving change, and leap seconds require a timescale-aware calculation. Use the Date Calculator for date additions and calendar gaps, or the time-zone tool for local clock comparisons.
Small time units
A millisecond is one thousandth of a second, a microsecond is one millionth, and a nanosecond is one billionth. Scientific notation keeps very small measurements readable. Zero is valid; a signed offset should instead be handled as addition or subtraction in the time calculator.
Formula
minutes = hours × 60
seconds = days × 86,400
1 fixed 365-day year = 31,536,000 seconds
1 Julian year = 31,557,600 seconds
Examples
Decimal hours
2.5 hours × 60 = 150 minutes, or 9,000 seconds.
A small interval
250 milliseconds is 0.25 seconds, or 250,000 microseconds.
Precision and definitions
Calculations retain unrounded values internally. Displayed digits do not increase the accuracy of measurements. NIST unit definitions provide the conversion reference.