Days to Hours
An instant days-to-hours converter, with the formula and a reference table below.
| Days | Hours |
|---|---|
| 1 day | 24 hr |
| 2 day | 48 hr |
| 3 day | 72 hr |
| 5 day | 120 hr |
| 10 day | 240 hr |
| 25 day | 600 hr |
| 50 day | 1200 hr |
| 100 day | 2400 hr |
How to use
- Enter a value in the Days field.
- The Hours figure appears immediately — no button to press.
- Typing in the Hours field converts back to Days the same way.
- Use the reference table for the values that come up most often.
Days to Hours formula
Converting days to hours is a single multiplication by 24.
hr = day × 24
Put another way, one day is exactly 24 hours.
Why this factor: the day and the hour are both defined against the second, so dividing one definition by the other gives 24 directly. Both definitions are set out in full below.
To go the other way, divide by 24 — or use the Hours to Days converter, which is the same calculation reversed.
Worked example
Start with 15 day. Multiply by 24 to get 360 hr.
15 day × 24 = 360 hr
The converter above does this for any value you type, in either direction.
What is a day?
A day is 24 hours, one nominal rotation of the Earth.
Definition: Exactly 86,400 seconds by convention. The Earth's actual rotation drifts slightly, which is what leap seconds correct.
Where it is used: Calendars, project schedules, hotel and rental periods, and interest accrual.
What is an hour?
An hour is sixty minutes — the primary unit of the working day.
Definition: Exactly 3,600 seconds.
Where it is used: Work and billing time, flight durations, and energy quantities such as the kilowatt-hour.
Days vs Hours
The day and the hour belong to the same family of units, so converting between them is usually a matter of shifting a decimal point or applying a small whole-number factor.
Frequently asked questions
How many hours are in a day?
One day equals 24 hours.
What is the formula to convert days to hours?
Multiply the number of days by 24. To reverse it, divide by 24 instead.
How do I convert hours back to days?
Divide by 24, which is the same as multiplying by 0.0416666667.
How many hours are in 10 days?
10 day works out to 240 hr.
How is the day defined?
Exactly 86,400 seconds by convention. The Earth's actual rotation drifts slightly, which is what leap seconds correct.