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Relativistic Velocity Addition Calculator

Adds two velocities correctly under special relativity so the result never exceeds the speed of light. Essential when objects move at a significant fraction of c.

First Velocity (m/s)

Second Velocity (m/s)

Fill in the required fields to see your result.

Relativity

Relativistic Escape Velocity Calculator

Calculates the escape velocity from a massive body using a relativistic correction for the Schwarzschild geometry. Useful for neutron stars, white dwarfs, and objects near black hole thresholds.

Mass of Object (kg)

Radius (meters)

Fill in the required fields to see your result.

Key differences

	Relativistic Velocity Addition Calculator	Relativistic Escape Velocity Calculator
Category	Relativity	Relativity
Inputs required	2	2
Result	Combined Velocity (m/s)	Escape Velocity (fraction of c)
What it does	Adds two velocities correctly under special relativity so the result never exceeds the speed of light. Essential when objects move at a significant fraction of c.	Calculates the escape velocity from a massive body using a relativistic correction for the Schwarzschild geometry. Useful for neutron stars, white dwarfs, and objects near black hole thresholds.