Quick Answer: Days to Hours
One day equals 24 hours (1 day = 24 hr).
Conversely, 1 hr = 0.0416666667 day.
Formula: hr = day × 24
Worked examples
- 0.5 day = 12 hr
- 1 day = 24 hr
- 2 day = 48 hr
Method and limitations
To convert days to hours, multiply the day value by 24. There are exactly 24 hours in one day. Calculations use full-precision constants; displayed values are rounded to at most 9 significant figures. Results are rounded for display only. Full precision is kept internally, so long chains of conversions do not accumulate rounding error. Where US customary and imperial units share a name (for example fluid ounces and gallons), this page uses the US customary definition and says so explicitly.
Each factor is exact by definition, derived from exact definitions, or a documented conventional value — see the methodology and sources.
Conversion Formula
To convert days to hours, multiply the day value by 24. There are exactly 24 hours in one day.
Complete Guide to Days to Hours Conversion
What is a Days?
A day is the time it takes for Earth to complete one rotation on its axis relative to the Sun, standardized at exactly 24 hours.
What is a Hours?
An hour is 1/24th of a day, providing a convenient division for scheduling, work shifts, and daily activities.
How the Conversion Works
Multiply days by 24 to get hours. This conversion is exact and has been standardized for millennia.
Why This Conversion Matters
Converting days to hours is essential for project management, travel planning, billing, and any situation requiring detailed time accounting.
Step-by-Step Conversion Guide
Follow these steps to convert days to hours manually:
Start with your value in days
Example: You want to convert 2 day
Apply the conversion formula
Use the formula: hr = day × 24
Calculate the result
2 day = 48 hr
Verify your answer
Use our calculator above to double-check your manual calculation.
Quick Mental Math Tip
To convert days to hours, multiply the day value by 24. There are exactly 24 hours in one day.
Common Conversions
| Days (day) | Hours (hr) | Hours → Days |
|---|---|---|
| 0.5 day | 12 | 0.5 hr = 0.0208333 day |
| 1 day | 24 | 1 hr = 0.0416667 day |
| 2 day | 48 | 2 hr = 0.0833333 day |
| 3 day | 72 | 3 hr = 0.125 day |
| 5 day | 120 | 5 hr = 0.208333 day |
| 7 day | 168 | 7 hr = 0.291667 day |
| 14 day | 336 | 14 hr = 0.583333 day |
| 30 day | 720 | 30 hr = 1.25 day |
| 60 day | 1,440 | 60 hr = 2.5 day |
| 90 day | 2,160 | 90 hr = 3.75 day |
| 365 day | 8,760 | 365 hr = 15.2083 day |
Did You Know?
A solar day is not exactly 24 hours — Earth's rotation is gradually slowing, which is why we occasionally add leap seconds.
This converter is used by thousands of people daily for quick reference. Bookmark it for instant access.
Popular Days to Hours Conversions
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When You'll Need This Conversion
Project Deadline Calculation
Convert project duration from days to work hours for resource planning and scheduling.
Trip Duration Planning
Calculate total travel hours for multi-day journeys and road trips.
Medication Schedules
Convert prescription duration from days to hours for precise dosing intervals.
Rental Calculations
Convert daily rental periods to hours for equipment, vehicles, or services.
Pro Tips for Accurate Conversions
Quick reference points
1 day = 24 hrs, 1 week = 168 hrs, 1 month ≈ 720 hrs, 1 year ≈ 8,760 hrs.
Work day vs calendar day
A work day is typically 8 hours, but a calendar day has 24 hours. Clarify which you need.
Common Mistakes to Avoid
Confusing work days with calendar days
A 5-day work week has 40 work hours, but 120 calendar hours (5 × 24).
Specify whether you're counting work hours (8/day) or calendar hours (24/day).
History & Background
The 24-hour day originated in ancient Egypt, where sundials divided daylight into 12 hours. Later, the night was also divided into 12 hours, creating the 24-hour cycle.
Global Usage Today
The 24-hour day is universal, used by every culture and time zone on Earth.
Frequently Asked Questions
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Conversion factors on this page are either exact by definition, derived from exact definitions, or conventional values in documented use. Each is listed with its source in our conversion methodology and sources, which cites the BIPM SI Brochure, NIST Special Publication 811 and the relevant IEC or national standards. Results are rounded for display only; calculations use full precision.