What this calculator does
Circular orbital velocity works out speed and period needed to hold a circular orbit around a mass. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulav = √(GM/r); T = 2πr/v, G = 6.67430×10⁻¹¹ m³/(kg·s²)
The inputs explained
| Field | What to enter |
|---|---|
| Mass of the central body (kg) | A number, measured in kg. Starts at 5.972e+24. |
| Orbital radius (km) | A number, measured in km. Starts at 6771. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with mass of the central body
Every other input is held at the calculator’s starting values while mass of the central body varies. Select any row to load that scenario into the calculator.
How the answer changes with mass of the central body
| Mass of the central body (kg) | Orbital velocity | Orbital period | Orbital period |
|---|---|---|---|
| 2,986,000,000,000,000,000,000,000 | 5.425 km/s | 130.7 minutes | 2.18 hours |
| 4,479,000,000,000,000,000,000,000 | 6.645 km/s | 106.7 minutes | 1.78 hours |
| 5,972,000,000,000,000,000,000,000 | 7.672 km/s | 92.4 minutes | 1.54 hours |
| 8,958,000,000,000,000,000,000,000 | 9.397 km/s | 75.5 minutes | 1.26 hours |
| 11,944,000,000,000,000,000,000,000 | 10.851 km/s | 65.3 minutes | 1.09 hours |
| 17,916,000,000,000,000,000,000,000 | 13.289 km/s | 53.4 minutes | 0.89 hours |