Free Roche Limit Calculator
Calculate the Roche limit, the minimum distance at which a self-gravitating satellite can orbit without tidal disruption.
m
kg/m³
kg/m³
Roche Limit (Rigid)
64,702,628 m
Roche Limit (Fluid)125,297,153 m
Roche Limit (Rigid) vs Primary Body Radius
The Roche Limit
Within the Roche limit, tidal forces from the primary exceed the self-gravity holding the satellite together.
Rigid Body
d_rigid = 1.26 R_p (rho_p / rho_s)^(1/3)
Fluid Body
d_fluid = 2.44 R_p (rho_p / rho_s)^(1/3)
Planetary rings typically exist inside the Roche limit.
Example Calculation
Rocky moon (rho = 3346 kg/m³) around Jupiter (R = 69 911 km, rho = 1326 kg/m³).
- 01rho_p / rho_s = 1326 / 3346 = 0.3963
- 02(0.3963)^(1/3) = 0.7347
- 03Rigid: 1.26 × 69 911 000 × 0.7347 ≈ 64 700 km
- 04Fluid: 2.44 × 69 911 000 × 0.7347 ≈ 125 300 km