Relativistic Velocity Addition Calculator
Add velocities according to special relativity velocity addition formula
About this calculator
The Relativistic Velocity Addition Calculator computes the combined velocity when two objects move at high speeds using Einstein's special relativity formula. Unlike classical physics where velocities simply add together, relativistic effects become significant at speeds approaching the speed of light. This calculator is essential for physics students, researchers, and anyone studying particle physics, astronomy, or space travel scenarios where objects move at substantial fractions of light speed.
How to use
Enter the first velocity and second velocity in the input fields, selecting your preferred units (m/s, km/s, or as fraction of light speed). Click calculate to get the relativistic sum. The result shows how the combined velocity differs from simple addition due to relativistic effects.
Frequently asked questions
Why can't velocities exceed the speed of light?
Einstein's relativity shows that as velocity approaches light speed, the relativistic factor approaches infinity, making faster-than-light travel impossible for objects with mass.
When do relativistic effects become important?
Relativistic effects become noticeable when velocities exceed about 10% of light speed (30,000 km/s), and are crucial above 50% light speed.
How does this differ from classical velocity addition?
Classical physics simply adds velocities (v1 + v2), while relativistic addition uses the formula (v1 + v2)/(1 + v1v2/c²) to prevent exceeding light speed.