Quick example
Convert 90 minutes to hours
Divide 90 minutes by 60 minutes per hour. The result is 1.5 hours, which is the same duration as 1 hour and 30 minutes or 5,400 seconds.
Quick reference
Common time duration conversions
| Starting duration | Equivalent |
|---|---|
| 1 second | 1,000 milliseconds |
| 1 minute | 60 seconds |
| 1 hour | 60 minutes |
| 1 hour | 3,600 seconds |
| 1 day | 24 hours |
| 1 day | 86,400 seconds |
| 1 week | 7 days |
| 1 week | 168 hours |
Fixed units
Elapsed duration, not calendar dates
Milliseconds to hours
These units have exact, fixed relationships: 1,000 milliseconds per second, 60 seconds per minute, and 60 minutes per hour.
Days and weeks
The converter uses conventional 24-hour days and seven-day weeks, giving exactly 86,400 seconds per day and 604,800 per week.
Months
A calendar month can contain 28, 29, 30, or 31 days, so it cannot be converted exactly without specific dates or an averaging convention.
Years
A calendar year can contain 365 or 366 days. Omitting years prevents a rounded assumption from looking like an exact result.
Clock and calendar boundaries
What this converter does not adjust
This tool converts an elapsed amount, not a start and end timestamp. It does not adjust for time zones, daylight saving changes, leap seconds, business days, or calendar boundaries. Those calculations require dates, locations, or additional conventions. Displayed results use up to 12 significant digits.
Common questions
Time duration conversion FAQ
How many hours is 90 minutes?
90 minutes equals 1.5 hours, or 1 hour and 30 minutes.
How many seconds are in a day?
One conventional 24-hour day contains exactly 86,400 seconds.
How many hours are in a week?
One seven-day week contains exactly 168 hours.
Why are months and years not included?
Calendar months have 28 to 31 days, and calendar years have 365 or 366 days, so neither is a fixed duration without an additional convention.
Can I convert decimal time values?
Yes. Decimal values are supported. For example, 2.5 hours equals 150 minutes.