Days to Hours Converter
Convert days to hours and back. 1 day = 24 hours exactly.
Tip: Results show up to 8 significant digits. The factors and their sources are listed on the "Where our numbers come from" page.
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Days and Hours
One day is exactly 24 hours, and one hour is about 0.0416666666667 days. The converter works both ways: use the two tabs at the top of the tool to choose the direction.
Quick conversion table
Days to Hours
| Days | Hours |
|---|---|
| 0.5 d | 12 h |
| 1 d | 24 h |
| 2 d | 48 h |
| 3 d | 72 h |
| 5 d | 120 h |
| 7 d | 168 h |
| 10 d | 240 h |
| 14 d | 336 h |
| 30 d | 720 h |
| 90 d | 2,160 h |
| 180 d | 4,320 h |
| 365 d | 8,760 h |
Hours to Days
| Hours | Days |
|---|---|
| 12 h | 0.5 d |
| 24 h | 1 d |
| 48 h | 2 d |
| 72 h | 3 d |
| 96 h | 4 d |
| 120 h | 5 d |
| 168 h | 7 d |
| 240 h | 10 d |
| 336 h | 14 d |
| 720 h | 30 d |
| 2,160 h | 90 d |
| 8,760 h | 365 d |
Exact factor and source
| Conversion | Value | Basis |
|---|---|---|
| 1 day in hours | 24 | exact. SI Brochure, 9th edition (BIPM 2019): Table 8, the day is accepted for use with the SI; 1 d = 86,400 s |
| 1 hour in days | 0.0416666666667 | rounded to 12 digits. SI Brochure, 9th edition (BIPM 2019): Table 8, the hour is accepted for use with the SI; 1 h = 3600 s |
How to convert days to hours
- Step oneTake the number of days.
- Step twoMultiply it by 24.
- Step threeThe result is the number of hours.
- Step fourTo go back, divide by 24, or multiply by 0.0416666666667.
Example: 7 d x 24 = 168 h.
All time units compared
Each unit written in seconds, the base unit of this tool. Exact values come straight from the definitions.
| Unit | Symbol | Value in seconds |
|---|---|---|
| Seconds | s | 1 second |
| Minutes | min | 60 seconds |
| Hours | h | 3,600 seconds |
| Days | d | 86,400 seconds |
| Weeks | wk | 604,800 seconds |
What is a day?
A day (d) is 24 hours or 86,400 seconds. This tool counts a civil day and ignores leap seconds.
What is a hour?
An hour (h) is 60 minutes or 3,600 seconds. It is not an SI unit but is accepted for use with SI.
What this converter does not do
- Results are rounded for display to 8 significant digits; the stored factor is the exact one.
- A day is exactly 24 hours here: leap seconds and daylight saving shifts are ignored.
- It does not convert to calendar months or years, because they have different lengths.
Frequently asked questions
How many hours are in a day?
1 day is exactly 24 hours. That factor is exact by definition.
How many days are in a hour?
1 hour is about 0.0416666666667 days.
How many hours are in 30 days?
30 days is 720 hours.
Where do the factors come from?
Days: SI Brochure, 9th edition (BIPM 2019): Table 8, the day is accepted for use with the SI; 1 d = 86,400 s. Hours: SI Brochure, 9th edition (BIPM 2019): Table 8, the hour is accepted for use with the SI; 1 h = 3600 s.
References
- Days: SI Brochure, 9th edition (BIPM 2019): Table 8, the day is accepted for use with the SI; 1 d = 86,400 s
- Hours: SI Brochure, 9th edition (BIPM 2019): Table 8, the hour is accepted for use with the SI; 1 h = 3600 s
- NIST Special Publication 811: Guide for the Use of the International System of Units (SI), 2008 edition.
- The International System of Units (SI Brochure), 9th edition, BIPM.