Planet Day Length Calculator
Result
Rotation period (hours)24.6229
Rotation period (Earth days)1.0259541667
↗ Space
Compare the approximate sidereal rotation period of the eight planets.
Formula
Earth days = Rotation period in hours ÷ 24
- Choose a planet to see the approximate time it takes to rotate once relative to the stars, expressed in Earth hours and Earth days.
- The main inputs are Planet. Enter them in the units and format shown in the calculator.
- Use the units, labels and assumptions shown beside each input so the formula is applied consistently.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Planet Day Length
Inputs
- Planet: mars
Mars rotates once in about 24.62 Earth hours.
Sample result: Calculating…
Frequently asked questions
What does this calculator estimate?
It shows an approximate sidereal rotation period for the selected planet.
Is this an exact mission-planning tool?
No. It is an educational calculator based on the stated constants and simplified assumptions.
How accurate is the result?
Values are rounded reference periods. Venus rotates retrograde; the calculator reports the absolute duration.
What does the Planet Day Length calculate?
Compare the approximate sidereal rotation period of the eight planets.
Which values should I enter?
Enter Planet using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: Earth days = Rotation period in hours ÷ 24.