Enter altitude and latitude, then click Calculate g.

Gravitational acceleration (g) is the acceleration of an object due to the gravitational force of a massive body. On Earth, g varies with altitude, latitude, and local geological conditions. The theoretical calculation uses Newton's law of universal gravitation: g = GM/(r²), where G is the gravitational constant, M is Earth's mass, and r is the distance from Earth's center. However, the effective value of g measured on the surface also includes the centripetal acceleration due to Earth's rotation, which is greatest at the equator and zero at the poles. The combined effect yields the standard value g₀ = 9.80665 m/s² at sea level and 45° latitude. The formula used is g_eff = √(g_grav² + a_cp² - 2·g_grav·a_cp), where a_cp = ω²·r·cos(φ) is the centripetal acceleration component perpendicular to the gravitational vector. This calculator is essential for physics, engineering, and geophysics applications.

1. Enter the Altitude in kilometers above sea level.
2. Enter the Latitude in degrees (-90° to 90°).
3. Click Calculate g to compute gravitational acceleration.
4. The result shows g in m/s², fraction of standard g, and component values.
5. Reference values are provided for comparison.
6. Click Reset to restore default example values.