Physics

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Acceleration Due to Gravity Calculator.

Calculate Newtonian gravitational acceleration from source mass and distance.

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Acceleration: 9.819973

Acceleration

9.819973

Educational physics model using the stated SI assumptions; verify engineering and safety decisions independently.

Use Cases

Physics homework and study

Quickly verify gravitational acceleration values for various masses and distances, helping students understand the inverse-square law.

Example: Calculate g at the surface of Mars using its mass and radius.

Space mission planning

Estimate gravitational pull at different altitudes to plan satellite orbits or lander descent profiles.

Example: Find g at 400 km above Earth's surface.

Frequently Asked Questions

How is gravitational acceleration calculated?
The calculator uses Newton's law of universal gravitation: g = G * M / r², where G is the gravitational constant (6.674×10⁻¹¹ N·m²/kg²), M is the source mass in kg, and r is the distance from the center in meters. The result is the acceleration in m/s².
What does 'distance from center' mean?
It is the distance from the center of the source mass to the point where you want to calculate the acceleration. For Earth, this is the radius plus altitude above the surface. The calculator uses this distance in meters.
Can I use this for any planet or object?
Yes, as long as you know the mass of the object (in kg) and the distance from its center (in meters). For example, for Earth, use mass 5.972×10²⁴ kg and distance 6.371×10⁶ m to get approximately 9.8 m/s².

Tips & Common Mistakes

Tips

  • Use consistent units: mass in kilograms (kg) and distance in meters (m) to get acceleration in m/s².
  • For Earth's surface, use mass 5.972×10²⁴ kg and distance 6.371×10⁶ m to get about 9.8 m/s².
  • Remember that distance is from the center of the mass, not from its surface. Add the radius to altitude if needed.
  • The result is an approximation assuming a spherical, uniform mass distribution; real planets have variations.

Common Mistakes to Avoid

  • Using the radius of the planet instead of the distance from the center when calculating at altitude.
  • Forgetting to convert units, such as using kilometers instead of meters for distance.
  • Confusing mass with weight; the calculator uses mass in kg, not force in newtons.

Last updated: August 13, 2026