How to use the gravitational redshift calculator
Find how much light from the surface of a massive body is shifted to longer wavelengths by gravity. Enter mass of body, radius of emission in the fields above; the gravitational redshift factor z, redshift in ppm are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “gravitational redshift”, “light escaping gravity”, “redshift of the Sun”, “calculate gravitational redshift”, “find gravitational redshift factor z”.
Formula
Variables
- M — Mass of body (kg)
- R — Radius of emission (m)
Worked example
With mass of body = 1.989e30 kg, radius of emission = 6.96e8 m, the calculator gives gravitational redshift factor z ≈ 2.1222 × 10⁻⁶; redshift in ppm ≈ 2.122224 ppm.
Frequently asked questions
What is the gravitational redshift calculator used for?
Find how much light from the surface of a massive body is shifted to longer wavelengths by gravity. It helps with questions such as “gravitational redshift”, “light escaping gravity”, “redshift of the Sun”.
What is the formula for the gravitational redshift calculation?
Gravitational redshift factor z = 1 / √(1-2 × GCONST × M / (CLIGHT × CLIGHT × R))-1. Redshift in ppm (ppm) = [Gravitational redshift factor z] × 1e6. Here M is mass of body (kg), R is radius of emission (m).
What inputs do I need for the gravitational redshift calculator?
You need mass of body in kg, radius of emission in m. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the gravitational redshift calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the gravitational redshift result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.