Time Converter
Most time units are fixed, but months and years are not — a month is 28 to 31 days and a year is 365 or 366. This converter uses the Gregorian calendar average (365.2425 days per year) so results are consistent and defensible.
Last updated — conversions use exact unit definitions, so results stay accurate.
| Unit | Value |
|---|
How it works
Below the day, time is decimal-free but exact: 1,000 milliseconds in a second, 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day. All conversions in that range are exact multiplications.
Above the day, calendar reality intrudes. A month is 28, 29, 30 or 31 days, so any single "month" value is an approximation. This converter uses the Gregorian average month of 30.436875 days, which is the right choice for totals spanning many months — payroll, subscriptions, project estimates.
The year uses 365.2425 days, the Gregorian calendar average that accounts for the leap year rules (divisible by 4, except centuries, except centuries divisible by 400). That is why a year here is 31,556,952 seconds rather than the 31,536,000 you get from a flat 365 days.
If you need an exact figure for a specific date range — say, interest accrued between two dates — use a date calculator instead. An average month will be off by up to about three days for any individual month, which matters for legal or financial deadlines.
Common time conversions
| From | To |
|---|---|
| 1 minute | 60 seconds |
| 1 hour | 3,600 seconds |
| 1 day | 86,400 seconds |
| 1 week | 604,800 seconds |
| 1 week | 168 hours |
| 1 month (avg) | 730.5 hours |
| 1 year (Gregorian) | 365.2425 days |
| 1 year (Gregorian) | 8,765.82 hours |
| 1 year (Gregorian) | 31,556,952 seconds |
Frequently asked questions
How many seconds are in a day?
Exactly 86,400: 24 hours × 60 minutes × 60 seconds. A week is 604,800 seconds and an average Gregorian year is 31,556,952 seconds.
How many hours are in a year?
An average Gregorian year has 8,765.82 hours (365.2425 days × 24). A common calendar year has 8,760 hours and a leap year has 8,784 hours. The average is the right figure for multi-year estimates.
Why is a month not a fixed number of days?
Calendar months range from 28 to 31 days, so no single value is exact for every month. This converter uses the Gregorian average of 30.436875 days, which is accurate over long spans but can differ by up to about three days for any specific month.
What is the Gregorian year length used here?
365.2425 days, or 31,556,952 seconds. It reflects the leap year rules — every fourth year, except centuries, unless the century is divisible by 400 — which is why 2000 was a leap year but 1900 was not.
How do I convert milliseconds to seconds?
Divide by 1,000. A 250 ms response time is 0.25 seconds. Milliseconds are widely used in performance work because web and API latencies are usually well under a second.