How to use the stellar radius from luminosity calculator
Find the radius of a star from its luminosity and surface temperature. Enter luminosity, surface temperature in the fields above; the radius are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “star radius from brightness”, “stellar size”, “Stefan Boltzmann star radius”, “calculate stellar radius from luminosity”, “find radius”.
Formula
Variables
- Lsun — Luminosity (solar luminosities)
- T — Surface temperature (K)
Worked example
With luminosity = 1 solar luminosities, surface temperature = 5772 K, the calculator gives radius ≈ 1.000001 solar radii; radius ≈ 695,700.8 km.
Frequently asked questions
What is the stellar radius from luminosity calculator used for?
Find the radius of a star from its luminosity and surface temperature. It helps with questions such as “star radius from brightness”, “stellar size”, “Stefan Boltzmann star radius”.
What is the formula for the stellar radius from luminosity calculation?
Radius (solar radii) = √(Lsun × 3.828e26 / (4 × π × SIGMA × T^4)) / 6.957e8. Radius (km) = [Radius] × 695700. Here Lsun is luminosity (solar luminosities), T is surface temperature (K).
What inputs do I need for the stellar radius from luminosity calculator?
You need luminosity in solar luminosities, surface temperature in K. 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 stellar radius from luminosity 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 stellar radius from luminosity 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.