Orbital Period & Velocity

Calculate orbital velocity and period for a circular orbit around Earth. Input either altitude above surface or distance from Earth's center. Assumes a spherical Earth (6371 km radius) and neglects atmospheric drag.

Orbit Visualization

Calculated Orbit
Hover over the orbit or Earth for details.

Hover over the visualization
to see orbit details.

Calculation Notes & Theory

  • Calculations are for circular orbits around Earth.
  • Assumes a perfectly spherical Earth with standard gravitational parameter (μ = GM) and radius.
  • Does not account for atmospheric drag, gravitational anomalies, or perturbations from other celestial bodies (like the Moon or Sun).
  • Velocity is the tangential speed required to maintain the circular orbit, calculated as v = √(μ / r), where r is the orbital radius (Earth radius + altitude).
  • Period is the time taken to complete one full orbit, calculated as T = 2π √(r³ / μ).

Open Source & Transparent

This tool is open source and the underlying logic is fully transparent. You can view the source code, understand the calculations, and even contribute improvements to make it better for everyone.

View Source Code