iSolveTo← Space & Astronomy
🛰️ Space & Astronomy

Astronomical Speed Converter

Convert astronomical speeds between m/s, km/s, km/h, mph and fractions of the speed of light.

Free toolGlobal unitsMobile friendly

Enter values

Use the inputs below to calculate the result.

Result

Calculated value—
Uses standard astronomy constants; results are mathematical estimates and should not replace mission-grade ephemerides or navigation data.

How it works

Convert astronomical speeds between m/s, km/s, km/h, mph and fractions of the speed of light.

Convert input to m/s, then to the selected output unit

How to use this calculator

What to enter

Enter or select the following as requested: Speed (value); Input unit; Output unit. Follow the units, valid ranges, examples, and options displayed beside each field.

What the result means

The astronomy result converts or estimates a distance, time, brightness, gravity, or orbital quantity from the entered astronomical values and model. Check the units, reference frame, object assumptions, and whether the formula uses idealized orbital or observational conditions.

When to use it

Use this for astronomy learning or preliminary calculations. Confirm the units and scientific model and consult reliable observational data when precision matters.