Time • NIST Exact

Hours Days

h → d

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NIST Exact

Based on U.S. National Institute of Standards

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Hours to Days Formula

To convert from Hours to Days, you can use the following formula:

Days = Hours × NaN

This means you need to multiply your Hours value by NaN to get the equivalent value in Days.

h → d Reference Table

h d
0.001 h 0.00004166666667 d
0.002 h 0.00008333333333 d
0.003 h 0.000125 d
0.004 h 0.0001666666667 d
0.005 h 0.0002083333333 d
0.006 h 0.00025 d
0.007 h 0.0002916666667 d
0.008 h 0.0003333333333 d
0.009 h 0.000375 d
0.01 h 0.0004166666667 d
0.02 h 0.0008333333333 d
0.03 h 0.00125 d
0.04 h 0.001666666667 d
0.05 h 0.002083333333 d
0.06 h 0.0025 d
0.07 h 0.002916666667 d
0.08 h 0.003333333333 d
0.09 h 0.00375 d
0.1 h 0.004166666667 d
0.2 h 0.008333333333 d
0.3 h 0.0125 d
0.4 h 0.01666666667 d
0.5 h 0.02083333333 d
0.6 h 0.025 d
0.7 h 0.02916666667 d
0.8 h 0.03333333333 d
0.9 h 0.0375 d
1 h 0.04166666667 d
1.5 h 0.0625 d
2 h 0.08333333333 d
2.5 h 0.1041666667 d
3 h 0.125 d
3.5 h 0.1458333333 d
4 h 0.1666666667 d
4.5 h 0.1875 d
5 h 0.2083333333 d
5.5 h 0.2291666667 d
6 h 0.25 d
6.5 h 0.2708333333 d
7 h 0.2916666667 d
7.5 h 0.3125 d
8 h 0.3333333333 d
8.5 h 0.3541666667 d
9 h 0.375 d
9.5 h 0.3958333333 d
10 h 0.4166666667 d
11 h 0.4583333333 d
12 h 0.5 d
13 h 0.5416666667 d
14 h 0.5833333333 d
15 h 0.625 d
16 h 0.6666666667 d
17 h 0.7083333333 d
18 h 0.75 d
19 h 0.7916666667 d
20 h 0.8333333333 d
25 h 1.041666667 d
30 h 1.25 d
35 h 1.458333333 d
40 h 1.666666667 d
45 h 1.875 d
50 h 2.083333333 d
55 h 2.291666667 d
60 h 2.5 d
65 h 2.708333333 d
70 h 2.916666667 d
75 h 3.125 d
80 h 3.333333333 d
85 h 3.541666667 d
90 h 3.75 d
95 h 3.958333333 d
100 h 4.166666667 d
120 h 5 d
125 h 5.208333333 d
130 h 5.416666667 d
140 h 5.833333333 d
150 h 6.25 d
160 h 6.666666667 d
175 h 7.291666667 d
180 h 7.5 d
200 h 8.333333333 d
225 h 9.375 d
250 h 10.41666667 d
275 h 11.45833333 d
300 h 12.5 d
350 h 14.58333333 d
400 h 16.66666667 d
450 h 18.75 d
500 h 20.83333333 d
600 h 25 d
700 h 29.16666667 d
750 h 31.25 d
800 h 33.33333333 d
900 h 37.5 d
1000 h 41.66666667 d
1200 h 50 d
1250 h 52.08333333 d
1500 h 62.5 d
1750 h 72.91666667 d
2000 h 83.33333333 d
2500 h 104.1666667 d
3000 h 125 d
4000 h 166.6666667 d
4500 h 187.5 d
5000 h 208.3333333 d
6000 h 250 d
7000 h 291.6666667 d
7500 h 312.5 d
8000 h 333.3333333 d
9000 h 375 d
10000 h 416.6666667 d
15000 h 625 d
20000 h 833.3333333 d
25000 h 1041.666667 d
50000 h 2083.333333 d
75000 h 3125 d
100000 h 4166.666667 d

Values based on NIST SP 811 conversion factors

Real-World Examples

One full day

24 h = 1 d

A standard work week

40 h = 1.666666667 d

Total hours in one week

168 h = 7 d

A long weekend (3 days)

72 h = 3 d

Total hours in one year

8760 h = 365 d

Why Convert Hours to Days?

Converting between hours (h) and days (d) is one of the most common time conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert h to d saves time and prevents errors.

Time conversion between h and d is essential for project management, astronomy, and high-speed electronics. While day-to-day scheduling is simple, scientific and engineering fields often require converting between vast timescales (millennia) and infinitesimal ones (nanoseconds). Video editors and audio engineers work with frames and samples that require precise time unit conversions to sync media perfectly. In logistics, accurate delivery estimates depend on converting travel durations across time zones and varying speed metrics. Miscalculating time units can lead to missed deadlines, data desynchronization, or navigation errors in GPS systems.

How to Convert Hours to Days

To convert hours to days, use the following formula:

d = h × 0.04166666667

Example: 1 h = 0.04166666667 d

For example, 5 h = 0.2083333333 d, 10 h = 0.4166666667 d, and 100 h = 4.166666667 d. For larger values, 1000 h = 41.66666667 d. Conversely, 1 d = 24 h. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Use Cases

  • One full day: 24 h = 1 d
  • A standard work week: 40 h = 1.666666667 d
  • Total hours in one week: 168 h = 7 d
  • A long weekend (3 days): 72 h = 3 d
  • Total hours in one year: 8760 h = 365 d

Common Mistakes to Avoid

  • Decimal time: thinking 1.50 hours is 1 hour 50 minutes (it's 1 hour 30 minutes).
  • Leap years: assuming every year has 365 days.
  • Month length: assuming all months are 30 days.

Pro Tips

  • Excel format: Be careful converting time in Excel; it stores dates as serial numbers.
  • Time zones: Always specify UTC offset when scheduling international calls.
  • Seconds in day: There are 86,400 seconds in a standard day.

What is a Hour?

The hour (h) is a unit of time equal to 60 minutes or 3,600 seconds. Historically defined as 1/24 of a day.

Hours are the standard unit for work shifts, travel duration, and daily scheduling worldwide.

What is a Day?

A unit of time based on Earth's rotation, equal to 24 hours.

Basic unit for daily life and calendars.

Frequently Asked Questions

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