Hill Sphere

Calculate hill sphere from multiple technical inputs.

How this calculator works

Enter semi-major axis (au), orbital eccentricity, planet mass (earth = 1), star mass (sun = 1). CalcStack applies the displayed formula and reports each intermediate planning value with the units shown.

Formula / method

Hill radius = a(1−e) × (planet mass ÷ (3 star mass))^(1/3)

Worked example

Use the documented default inputs to model hill sphere.

Assumptions and limitations

Inputs represent stable average operating conditions and the displayed equation applies.

This is a planning model; real systems and measurements can require domain-specific corrections.