Days to Hours Converter
1 day = 24 hours
Understanding how days relate to hours is important across project management, science, and history. The day is based on Earth's rotation period. In practice, 1 d equals 24 h.
Did you know? Did you know? The International Space Station orbits Earth about 16 times per day. Converting that to hours: that is approximately 384 hours.
Conversion Formula
hours = days x 24
To convert days to hours, multiply by 24. A day is defined as exactly 24 hours, though the actual solar day varies slightly (by milliseconds) due to Earth's rotation.
Days to Hours Table
| Days (d) | Hours (h) |
|---|---|
| 0.25 | 6 |
| 0.5 | 12 |
| 1 | 24 |
| 2 | 48 |
| 3 | 72 |
| 5 | 120 |
| 7 | 168 |
| 14 | 336 |
| 30 | 720 |
| 365 | 8760 |
About Days to Hours
The days-to-hours conversion is used in project management, emergency planning, travel logistics, and healthcare. While 1 day = 24 hours is basic knowledge, the actual calculation matters in many practical contexts.
In project management, effort is estimated in person-hours. A 5-day sprint is 120 hours of available team time (assuming 8-hour workdays per person, a 5-person team has 200 person-hours). A 30-day project has 720 total hours.
Emergency response measures critical windows in hours. The "golden hour" in trauma care refers to the first 60 minutes. A 72-hour emergency kit covers 72 hours (3 days). Food safety guidelines say perishables should not sit out for more than 2 hours (0.083 days).
Travel planning across time zones uses this conversion. A 14-hour flight from London to Sydney takes 0.583 days. Jet lag recovery is roughly one day per time zone crossed, so a 9-hour difference needs about 216 hours (9 days) to fully adjust.
Medical protocols often specify hours. Post-surgical monitoring for 48 hours means 2 days in the hospital. Medication prescribed "every 6 hours" means 4 times per day. A 24-hour urine collection is exactly 1 day.
A year contains 8,760 hours (365 x 24), or 8,784 in a leap year. The average person sleeps about 2,920 hours per year (8 hours x 365 days), leaving 5,840 waking hours.
Frequently Asked Questions
How many hours in a day?
There are exactly 24 hours in 1 day. This equals 1,440 minutes or 86,400 seconds.
How many hours in a week?
There are 168 hours in a week (7 days x 24 hours). A standard 40-hour workweek uses about 24% of the total hours.
How many hours in a year?
A regular year has 8,760 hours (365 x 24). A leap year has 8,784 hours (366 x 24).
Why do we have 24 hours in a day?
Ancient Egyptians divided daylight into 12 hours and nighttime into 12 hours, totaling 24. This was influenced by the Babylonian base-12 counting system. The convention has persisted for over 3,500 years.