Stellar Mass Calculator

Calculate stellar mass using mass-luminosity relation, mass-radius relation, and orbital dynamics.

Inputs

Luminosity

Solar Luminosities

Radius

Solar Radii

Surface Temperature

Orbital Period (Binary)

days

Semi-Major Axis (Binary)

Tab to move between fields

Results

Estimated Mass

1 Solar Masses

Main Sequence Lifetime

10,000,000,000 billion years

Mass from Luminosity1 Solar Masses

Mass from Radius1 Solar Masses

Mass from Orbit0 Solar Masses

Surface Gravity274.28 m/s²

How to Use This Calculator

Enter Luminosity (solar luminosities), Radius (solar radii), and Surface Temperature (K) from spectrophotometry.
For a binary system, also enter Orbital Period (days) and Semi-Major Axis (AU) to enable the most precise mass estimate.
Read Estimated Mass (solar masses) — the best combined estimate from all available methods.
Compare Mass from Luminosity, Mass from Radius, and Mass from Orbit to assess measurement consistency.
Use Main Sequence Lifetime (billion years) and Surface Gravity (m/s²) to characterize the stellar evolutionary stage.

How the result changes with Radius

Radius	Estimated Mass	Main Sequence Lifetime
100	158.614 Solar Masses	0 billion years
350	757.429 Solar Masses	0 billion years
650	1,641.512 Solar Masses	0 billion years
900	2,465.252 Solar Masses	0 billion years

What each input means

Luminosity: Stellar luminosity
Radius: Stellar radius
Surface Temperature: Effective surface temperature
Orbital Period (Binary): Orbital period for binary system (0 if single star)
Semi-Major Axis (Binary): Semi-major axis for binary system

How this is calculated

Formula

M ∝ L^(1/3.5) (Mass-Luminosity Relation)

Worked example, using the default values

Identify Input Parameters
4 parameters
Luminosity = 1, Radius = 1, Surface Temperature = 5778, Orbital Period (Binary) = 0 = 5 input(s) provided
Calculate Estimated Mass
Estimated Mass
1 = 1
Calculate Main Sequence Lifetime
Main Sequence Lifetime
10000000000 = 10000000000
Calculate Mass from Luminosity
Mass from Luminosity
1 = 1
Calculate Mass from Radius
Mass from Radius
1 = 1

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

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Stellar Luminosity Calculator

Calculate stellar luminosity using Stefan-Boltzmann law. Find absolute magnitude, main sequence lifetime, and stellar parameters.

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Orbital Period Calculator

Calculate orbital period using Kepler's laws. Find orbital velocity, angular velocity, and perihelion/aphelion distances.

Astronomy

Binary Star Orbit

Calculate the total mass of a binary star system from orbital period and semi-major axis using Kepler's Third Law.