Roche Limit Calculator

Calculate Roche limit - the minimum distance a satellite can orbit before being torn apart by tidal forces.

Primary Radius

Solar Radii

Primary Density

kg/m³

Secondary Density

kg/m³

Body Type

Tab to move between fields

Roche Limit

1,083,999.288 km

Roche Limit

0.0072 AU

Roche Limit1.56 Primary Radii

Stability Factor0.135

How to Use This Calculator

Enter the Primary Radius (solar radii) and Primary Density (kg/m³) of the central body — the Sun is 1 R☉ and ~1,408 kg/m³.
Enter the Secondary Density (kg/m³) of the orbiting satellite — rocky bodies ~5,500 kg/m³, icy bodies ~1,000 kg/m³.
Select Body Type: Fluid for soft bodies like comets or gas clouds; Rigid for solid rocky satellites.
Read Roche Limit (km) — any satellite orbiting inside this distance will be tidally disrupted and form a ring.
Compare the Roche Limit (AU) to your satellite's current orbital distance to assess disruption risk.

How the result changes with Primary Radius

d_Roche = 2.456 × R × (ρ_primary / ρ_secondary)^(1/3)

Identify Input Parameters
4 parameters
Primary Radius = 1, Primary Density = 1408, Secondary Density = 5514, Body Type = 0 = 4 input(s) provided
Calculate Roche Limit
Roche Limit
1083999.288 = 1083999.288
Calculate Roche Limit
Roche Limit
0.0072 = 0.0072
Calculate Roche Limit
Roche Limit
1.56 = 1.56
Calculate Stability Factor
Stability Factor
0.135 = 0.135