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Relativistic Velocity Addition Calculator

Computes the combined velocity of two objects moving at relativistic speeds, preventing any result from exceeding the speed of light. Use it when simple addition of velocities would violate special relativity.

Velocity 1 (m/s)

Velocity 2 (m/s)

Direction

Velocity Unit

Fill in the required fields to see your result.

Relativity

Relativistic Doppler Effect Calculator

Compute the observed frequency and wavelength when a light source moves toward or away from you at relativistic speeds. Used in astrophysics to analyze spectra of fast-moving stars, galaxies, and spacecraft.

Source Frequency (Hz)

Relative Velocity (c)

Motion Direction

Fill in the required fields to see your result.

Key differences

	Relativistic Velocity Addition Calculator	Relativistic Doppler Effect Calculator
Category	Relativity	Relativity
Inputs required	4	3
Result	Relativistic Sum (m/s)	Observed Frequency (Hz)
What it does	Computes the combined velocity of two objects moving at relativistic speeds, preventing any result from exceeding the speed of light. Use it when simple addition of velocities would violate special relativity.	Compute the observed frequency and wavelength when a light source moves toward or away from you at relativistic speeds. Used in astrophysics to analyze spectra of fast-moving stars, galaxies, and spacecraft.