7 FOCUSED TOOLS
Orbits & escape calculators
Explore ideal two-body orbital relationships.
Choose the right calculation
Use radius from the centre of the attracting body, not altitude above its surface. Choose the gravitational parameter of the correct primary. Drag, rotation and other bodies are excluded from these simple models.
Find a tool for your question
Kepler Orbital Period Calculator
Estimate a small body’s orbital period around a one-solar-mass star.
Circular Orbit Speed Calculator
Find ideal circular orbital speed around a body using its gravitational parameter.
Escape Velocity Calculator
Find ideal escape speed from a spherical body at a chosen centre distance.
Orbital Period From Mu Calculator
Find orbital period from central gravitational parameter and circular-orbit radius.
Surface Gravity From Mu Calculator
Estimate gravity at a spherical body’s surface from its gravitational parameter.
Elliptical Orbit Eccentricity Calculator
Find orbital eccentricity from extreme orbital distances.
Orbit Semi Major Axis Calculator
Find an ellipse’s semi-major axis from periapsis and apoapsis distances.
Can I use altitude directly as orbital radius?
No. Add the central body’s radius to altitude when a formula requires distance from its centre.
Useful next steps in other categories
Kinetic Energy Calculator
Find translational kinetic energy from mass and speed.
Centripetal Force Calculator
Find net inward force needed for uniform circular motion.