To convert hours to days, divide by 24. So 48 hours is 2 days, 72 hours is 3 days, 100 hours is 4 days and 4 hours, and 1,000 hours is 41 days and 16 hours. To go the other way, multiply days by 24.
Hours to days conversion table
| Hours | Days (decimal) | Days + hours |
|---|---|---|
| 24 | 1 | 1 day |
| 36 | 1.5 | 1 day 12 hours |
| 48 | 2 | 2 days |
| 60 | 2.5 | 2 days 12 hours |
| 72 | 3 | 3 days |
| 96 | 4 | 4 days |
| 100 | 4.17 | 4 days 4 hours |
| 120 | 5 | 5 days |
| 144 | 6 | 6 days |
| 168 | 7 | 1 week |
| 200 | 8.33 | 8 days 8 hours |
| 336 | 14 | 2 weeks |
| 500 | 20.83 | 20 days 20 hours |
| 720 | 30 | 30 days |
| 1,000 | 41.67 | 41 days 16 hours |
| 2,000 | 83.33 | 83 days 8 hours |
| 8,760 | 365 | 1 common year |
| 10,000 | 416.67 | 1 year, 51 days and 16 hours |
Turning the decimal into hours
Dividing often leaves a decimal. To turn it back into hours, multiply the decimal part by 24, or simply find the remainder:
- Divide: 100 ÷ 24 = 4.1667.
- Take the whole number: 4 days.
- Multiply the whole days back: 4 × 24 = 96 hours.
- Subtract: 100 − 96 = 4 hours left over.
So 100 hours = 4 days and 4 hours. The same method works for any number.
Hours to "work days"
If the hours are working time, such as project estimates, PTO balances or overtime, divide by the length of a workday instead of 24:
| Hours | 8-hour work days | 40-hour work weeks |
|---|---|---|
| 16 | 2 | 0.4 |
| 40 | 5 | 1 |
| 80 | 10 | 2 |
| 120 | 15 | 3 |
| 160 | 20 | 4 |
| 2,080 | 260 | 52 |
For example, a PTO balance of 120 hours is 15 days off on an 8-hour schedule, or 3 full weeks. If you work 7.5-hour days, divide by 7.5 instead: 120 ÷ 7.5 = 16 days. For annual totals, see working days in 2026 and 2027.
Where hour counts come up
- Return windows and deliveries: "within 72 hours" means 3 full days from the moment of the order, not 3 business days.
- Medical instructions: "every 48 hours" means once every two days at about the same time. Always follow the label or your clinician's directions.
- Fasting and challenges: a 36-hour fast is a day and a half; a 100-hour challenge is just over four days.
- Hobbies and skills: the popular "10,000 hours" idea equals about 417 days of nonstop practice, or roughly 5 years at 40 hours a week.
- Equipment and warranties: engines, filters and bulbs are often rated in hours; a 25,000-hour LED used 4 hours a day lasts over 17 years.
What time will it be after N hours?
Converting to days tells you the duration, but often you need the exact time. Add the whole days to the date, then add the leftover hours to the clock:
- It's 3:00 PM on Monday. In 50 hours (2 days and 2 hours) it will be 5:00 PM on Wednesday.
- It's 10:00 PM on Friday. In 30 hours (1 day and 6 hours) it will be 4:00 AM on Sunday.
Watch for daylight saving time changes, which add or remove an hour overnight. Our calculators handle that for you: try 48 hours from now, 72 hours from now or 168 hours from now. For clock arithmetic, see how to add or subtract hours from a time.
Days to hours, quickly: 1 day = 24 hours · 1 week = 168 hours · 30 days = 720 hours · 1 year = 8,760 hours (8,784 in a leap year). More in how many hours are in a year.
Frequently asked questions
How many days is 48 hours?
Exactly 2 days.
How many days is 72 hours?
Exactly 3 days.
How many days is 1,000 hours?
About 41.7 days, or 41 days and 16 hours.
How many days is 300 hours?
12.5 days, or 12 days and 12 hours.