Time Unit Converter

Convert between seconds, minutes, hours, days, weeks, months, and years with decimal precision.

Tested tool guide Tested browser tools Checked August 16, 2026

What Time Unit Converter does, with a checked example

Type a quantity and its unit, and the tool returns the same duration in every other unit as a decimal: 2.5 hours comes back as 150 minutes, 9000 seconds, and 0.1042 days. Minutes, hours, days, and weeks are exact fixed multiples of the second, so those conversions are always precise. The surprise is the two calendar units: months and years have no fixed length, so the tool pins them to a convention such as 30 or 30.44 days per month. A calendar month of 28 to 31 days will not match.

Worked example

A concrete input and expected output from the current implementation.

Input

15000 seconds

Expected output

250 minutes, 4.1667 hours, 0.1736 days, 0.0248 weeks

Every unit is a fixed multiple of the second, so each result is one division: 15000 / 60 = 250 minutes, 15000 / 3600 = 4.1667 hours, 15000 / 86400 = 0.1736 days, and 15000 / 604800 = 0.0248 weeks, rounded to four decimals. Month and year values are omitted because they depend on the fixed-length convention the converter uses.

How the result is produced

Fixed ratios to the second

Seconds, minutes, hours, days, and weeks have exact, universally agreed lengths: 60, 3600, 86400, and 604800 seconds. The converter expresses the entered quantity in seconds, then divides by the target unit's seconds, so any conversion among these five units is exact; the decimal you see is limited only by how many digits the display rounds to. One multiply, one divide, no calendar or clock involved.

Months and years are conventions

A month runs 28 to 31 days and a year 365 or 366, so no exact ratio exists for these two. The tool assigns each a fixed length, commonly 30 or 30.44 days for a month and 365 or 365.25 days for a year. Results are conventional: another converter with a different constant returns a different day count for the same input, while all tools agree on hours to weeks.

Good uses

Deadline math: a deployment window is 36 hours and the planning sheet wants days, which is 1.5, and this tool does the division instead of your head.
Timesheet to billing: a shift logger reports 285 minutes of work and the invoice needs hours, 4.75, so the client-facing number is right.
Log and config sanity checks: a service timeout is documented as 7200 seconds and you want to confirm that is 2 hours before you change it.

Limits and checks

Month and year results are conventional, not calendar-accurate. If the tool's constant is 30.44 days per month, 3 months comes out about 91.3 days, while any actual three-month span runs 89 to 92 days. Do not use month or year output for date arithmetic.
Output is a single decimal, not mixed units. 90 minutes returns 1.5 hours, never '1 hour 30 minutes'; 0.5 days is 12 hours, and 1.5 days is a day and a half, not one day plus five hours. If you need hh:mm notation, this tool is the wrong format.
The input is a decimal number, not clock or calendar notation. 2.30 means two and three-tenths hours, or 2 hours 18 minutes, not 2:30; a time of day like 9 AM or a date like March 15 is not a duration and belongs in a date tool, not this one.

Common questions

Why does 3 months convert to about 91 days when the calendar span I care about is different?

Because a month is not a fixed length, the converter uses one constant for every month. With a 30.44-day constant, 3 months is 91.3 days, which matches no single calendar span: the real total depends on which three months, from 89 days in a common-year February to April up to 92 days. Use the converter for estimates, and a calendar tool for date math.

Does it account for leap years and daylight saving time?

No. A year is a fixed number of days and a day is a fixed 24 hours, so a leap year's 366 days and a 23- or 25-hour daylight-saving day are invisible to it. For durations of weeks or less the difference is negligible; for anything where the exact calendar date matters, do the arithmetic on the calendar itself.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.