Hour to Sidereal Day Converter
Convert Hour (h) to Sidereal Day (sid day) instantly. 1 h = 0.041781 sid day.
Time Converter
21 units available
1 h = 0.041781 sid day
Formula:
sid day = h × 0.0417807462With your value: 1 h = 0.04178075 sid day
How big is that?
Everyday references on a logarithmic scale, all expressed in hour so you can sanity-check the result.
Other Hour to Sidereal Day conversions
Hour to Sidereal Day Conversion Table
| Hour (h) | Sidereal Day (sid day) |
|---|---|
| 0.5 | 0.02089 |
| 1 | 0.041781 |
| 2 | 0.083561 |
| 5 | 0.208904 |
| 10 | 0.417807 |
| 15 | 0.626711 |
| 20 | 0.835615 |
| 25 | 1.044519 |
| 50 | 2.089037 |
| 100 | 4.178075 |
| 250 | 10.445187 |
| 500 | 20.890373 |
| 1000 | 41.780746 |
Sidereal Day to Hour Conversion Table
| Sidereal Day (sid day) | Hour (h) |
|---|---|
| 0.5 | 11.967235 |
| 1 | 23.93447 |
| 2 | 47.868939 |
| 5 | 119.672348 |
| 10 | 239.344696 |
| 15 | 359.017044 |
| 20 | 478.689392 |
| 25 | 598.36174 |
| 50 | 1,196.723479 |
| 100 | 2,393.446958 |
| 250 | 5,983.617396 |
| 500 | 11,967.234792 |
| 1000 | 23,934.469583 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Hour (h)
Time
Traceable to the second, defined by fixing the caesium-133 hyperfine transition frequency at 9 192 631 770 Hz.
Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)
Bureau International des Poids et Mesures · Reviewed 2026-07-01
Sidereal Day (sid day)
Time
Traceable to the second, defined by fixing the caesium-133 hyperfine transition frequency at 9 192 631 770 Hz.
Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)
Bureau International des Poids et Mesures · Reviewed 2026-07-01
How to Convert Hour to Sidereal Day
To convert from Hour (h) to Sidereal Day (sid day), multiply the value by 0.0417807462.
Formula: sid day = h × 0.0417807462
Reverse: h = sid day × 23.9344695833
Step-by-Step Example
- Start with your value in Hour. For example: 5 h
- Multiply by the conversion factor: 5 x 0.0417807462
- The result is: 0.208904 sid day
About Hour
The hour (h) is a unit of time. One hour equals 3600 seconds. UnitConvertLab converts it against every other time unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
Common uses: time calculations, engineering and science, education.
About Sidereal Day
The sidereal day (sid day) is a unit of time. One sidereal day equals 86164.0905 seconds. UnitConvertLab converts it against every other time unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
Common uses: time calculations, engineering and science, education.
Frequently Asked Questions
How many Sidereal Day are in 1 Hour?
There are exactly 0.0417807462 Sidereal Day in 1 Hour. This means the conversion factor from Hour to Sidereal Day is 0.0417807462.
What is the formula to convert Hour to Sidereal Day?
The formula to convert Hour to Sidereal Day is: sid day = h × 0.0417807462. For example, to convert 10 Hour to Sidereal Day, you would multiply 10 by 0.0417807462.
What is a Hour?
The hour (h) is a unit of time. One hour equals 3600 seconds. UnitConvertLab converts it against every other time unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
What is a Sidereal Day?
The sidereal day (sid day) is a unit of time. One sidereal day equals 86164.0905 seconds. UnitConvertLab converts it against every other time unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
What are the common uses of Hour?
The Hour is commonly used in time calculations, engineering and science, education.
Related Time Conversions
Cite this page
UnitConvertLab. (2026). Hour to Sidereal Day converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/hour-to-sidereal_day