Convert Day to Hour
1 day = 24 hour (hr). For example, 10 day = 240 hour and 100 day = 2,400 hour. Type any value below to convert day to hour both ways — it runs entirely in your browser.
Quick answer: Day to Hour
1 Day = 24 Hour (day → hr). To convert day to hour, multiply by 24. To convert hour to day, multiply by 0.04166667. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common day-to-hour questions.
How to convert Day to Hour
To convert day to hour, multiply the number of day by the conversion factor 24, because 1 day = 24 hr. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 hr = 0.04166667 day, so you divide by 24 (or multiply by 0.04166667) to turn hour back into day.
hr = day × 24 ·
day = hr × 0.04166667
- Write down the value you want to convert, in day.
- Multiply it by 24.
- The result is the same area/length/quantity expressed in hour.
Day to Hour — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 day is 120 hour because 5 day × 24 = 120 hr.
| Day | Calculation | Hour |
|---|---|---|
| 1 day | 1 day × 24 = 24 hr | 24 hr |
| 2 day | 2 day × 24 = 48 hr | 48 hr |
| 3 day | 3 day × 24 = 72 hr | 72 hr |
| 5 day | 5 day × 24 = 120 hr | 120 hr |
| 7 day | 7 day × 24 = 168 hr | 168 hr |
| 10 day | 10 day × 24 = 240 hr | 240 hr |
| 12 day | 12 day × 24 = 288 hr | 288 hr |
| 15 day | 15 day × 24 = 360 hr | 360 hr |
| 20 day | 20 day × 24 = 480 hr | 480 hr |
| 25 day | 25 day × 24 = 600 hr | 600 hr |
| 50 day | 50 day × 24 = 1,200 hr | 1,200 hr |
| 100 day | 100 day × 24 = 2,400 hr | 2,400 hr |
Common Day to Hour conversions
These are the day-to-hour values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 day = 24 hour
- 2 day = 48 hour
- 2.5 day = 60 hour
- 3 day = 72 hour
- 4 day = 96 hour
- 5 day = 120 hour
- 6 day = 144 hour
- 7 day = 168 hour
- 8 day = 192 hour
- 9 day = 216 hour
- 10 day = 240 hour
- 12 day = 288 hour
- 15 day = 360 hour
- 20 day = 480 hour
- 25 day = 600 hour
- 30 day = 720 hour
- 50 day = 1,200 hour
- 75 day = 1,800 hour
- 100 day = 2,400 hour
- 200 day = 4,800 hour
- 500 day = 12,000 hour
- 1000 day = 24,000 hour
Day to Hour conversion chart (both directions)
The chart below converts day to hour and hour to day side by side, so it works whichever way you need. 1 day = 24 hour, and 1 hour = 0.04166667 day.
| Day → Hour | Hour → Day |
|---|---|
| 0.25 day = 6 hr | 0.25 hr = 0.01041667 day |
| 0.5 day = 12 hr | 0.5 hr = 0.02083333 day |
| 1 day = 24 hr | 1 hr = 0.04166667 day |
| 2 day = 48 hr | 2 hr = 0.08333333 day |
| 3 day = 72 hr | 3 hr = 0.125 day |
| 4 day = 96 hr | 4 hr = 0.1666667 day |
| 5 day = 120 hr | 5 hr = 0.2083333 day |
| 6 day = 144 hr | 6 hr = 0.25 day |
| 7 day = 168 hr | 7 hr = 0.2916667 day |
| 8 day = 192 hr | 8 hr = 0.3333333 day |
| 9 day = 216 hr | 9 hr = 0.375 day |
| 10 day = 240 hr | 10 hr = 0.4166667 day |
| 12 day = 288 hr | 12 hr = 0.5 day |
| 15 day = 360 hr | 15 hr = 0.625 day |
| 20 day = 480 hr | 20 hr = 0.8333333 day |
| 25 day = 600 hr | 25 hr = 1.041667 day |
| 30 day = 720 hr | 30 hr = 1.25 day |
| 40 day = 960 hr | 40 hr = 1.666667 day |
| 50 day = 1,200 hr | 50 hr = 2.083333 day |
| 75 day = 1,800 hr | 75 hr = 3.125 day |
| 100 day = 2,400 hr | 100 hr = 4.166667 day |
| 150 day = 3,600 hr | 150 hr = 6.25 day |
| 200 day = 4,800 hr | 200 hr = 8.333333 day |
| 250 day = 6,000 hr | 250 hr = 10.41667 day |
| 500 day = 12,000 hr | 500 hr = 20.83333 day |
| 1000 day = 24,000 hr | 1000 hr = 41.66667 day |
Day vs Hour: which is bigger?
A day is the larger unit: one day equals 24 hours. Put another way, you need 24 hours to make a single day.
What is a Day? History, origin and usage
The day is rooted in the rotation of the Earth on its axis, the most fundamental natural cycle of human life, and was divided into twenty-four hours following the Egyptian twelve-and-twelve scheme. For timekeeping it is now defined as exactly 86,400 SI seconds.
The day is the basic unit of calendars, daily planning and the human sleep-wake cycle, and it frames everything from deadlines to weather forecasts. Longer spans such as weeks, months and years are all built up from days.
A solar day, from one local noon to the next, is slightly longer than a sidereal day, the time for Earth to rotate once relative to the stars, which runs about four minutes shorter. Earth's rotation is very gradually slowing, which is why leap seconds are occasionally added to keep clocks aligned with the planet.
What is a Hour? History, origin and usage
The hour traces to the ancient Egyptians, who from around the second millennium BC divided daytime and night-time each into twelve parts, a custom later combined with Babylonian counting; the English word comes through Old French from the Greek hora. The familiar twenty-four-hour day grew out of those twelve daytime and twelve night-time hours.
The hour is the standard unit for work and wages, scheduling, travel times and broadcasting. It organises the daily rhythm of almost every society and underlies the 12- and 24-hour clock conventions.
Early hours were seasonal or temporal, meaning daytime hours were longer in summer and shorter in winter because daylight was always split into twelve. Only with mechanical clocks did fixed, equal-length hours become the norm.
Convert 1 Day to other units
It can help to see a day next to the other units it is commonly compared with. One day (day) is equal to:
| 1 Day equals | Unit |
|---|---|
| 86,400,000,000,000 ns | Nanosecond |
| 86,400,000,000 µs | Microsecond |
| 86,400,000 ms | Millisecond |
| 86,400 s | Second |
| 1,440 min | Minute |
| 24 hr | Hour |
| 0.1428571 wk | Week |
Convert 1 Hour to other units
One hour (hr) is equal to:
| 1 Hour equals | Unit |
|---|---|
| 3,600,000,000,000 ns | Nanosecond |
| 3,600,000,000 µs | Microsecond |
| 3,600,000 ms | Millisecond |
| 3,600 s | Second |
| 60 min | Minute |
| 0.04166667 day | Day |
| 0.005952381 wk | Week |
Tips for converting Day to Hour
- To go from day to hour, multiply by 24; to go back, divide by 24 (or multiply by 0.04166667).
- For a quick mental estimate, remember that 1 day ≈ 24 hour, so 10 day ≈ 240 hour.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this Day to Hour converter
Type a number into the Day field and the equivalent in Hour appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Hour field to convert the other way (hour to day). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 day = 24 hr), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for day-to-hour conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
- NIST — Definitions of the SI base units — the US National Institute of Standards and Technology reference for the SI base units, used here as an independent cross-check on the base-unit definition.
Frequently asked questions
- How many hour are in 1 day?
- 1 day = 24 hour (hr). To convert any number of day to hour, multiply by 24.
- How do I convert day to hour?
- Multiply the number of day by 24. For example, 10 day = 10 × 24 = 240 hour, and 25 day = 600 hour.
- How many day are in 1 hour?
- 1 hour = 0.04166667 day. So to convert hour back to day, multiply by 0.04166667.
- What is the formula to convert day to hour?
- hour = day × 24. The reverse formula is day = hour × 0.04166667.
- How much is 100 day in hour?
- 100 day = 2,400 hour. (And 1000 day = 24,000 hour.)
- Which is bigger, a day or a hour?
- A day is larger: 1 day = 24 hour.
- Is this day to hour converter accurate?
- Yes — every value is computed from the exact 24 hr per day factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert hour to day too?
- Yes. The converter works both ways — enter a value in either field. 1 hour = 0.04166667 day.