Introduction
The Gravitational Force Calculator helps you find the pull between any two objects in space. Every object with mass pulls on every other object with mass. This pull is called gravity. The bigger the objects are, the stronger they pull. The closer they are, the stronger the pull becomes.
This tool uses Newton's law of gravity to calculate the force between two masses. You can find the force between planets, moons, stars, or even everyday objects. The calculator can also work backwards - if you know the force and one mass, it can find the other mass. Or if you know both masses and the force, it can find how far apart they are.
Whether you're studying how the Moon pulls on Earth, how satellites stay in orbit, or just curious about gravity between everyday things, this calculator makes it easy. Just enter your values, pick your units, and get instant results with clear steps showing how the math works. For related physics calculations, try our Force Calculator for general force problems or the Free Fall Calculator to see gravity in action.
How to use our Gravitational Force Calculator
Enter the mass of two objects and the distance between them to find the force that pulls them together. You can also solve for any missing value if you know the other three.
Calculation Mode: Pick what you want to find - force, mass 1, mass 2, or distance. The calculator will hide the field you're solving for.
Mass 1: Type the weight of the first object. Use the number boxes for regular or scientific notation (like 5.972 × 10^24). Pick your unit from the dropdown menu or use a preset button for common objects.
Mass 2: Type the weight of the second object the same way as mass 1. You can choose different units for each mass.
Distance: Enter how far apart the centers of the two objects are. This must be greater than zero. Use preset buttons for common distances like Earth to Moon.
Gravitational Force: When solving for mass or distance, enter the known force between the objects here. When calculating force, this shows as your answer.
Calculate Button: Press this to get your answer. Turn on auto-calculate to see results update as you type.
Understanding Gravitational Force
Gravitational force is the pull between any two objects that have mass. This force exists between everything in the universe - from tiny particles to huge planets and stars. The bigger the objects are and the closer they are to each other, the stronger the pull becomes.
How Gravity Works
Every object with mass creates an invisible force field around it that pulls other objects toward it. When you drop a ball, Earth's gravity pulls it down. At the same time, the ball pulls on Earth too, but Earth is so much bigger that we don't notice Earth moving. The force between objects follows Newton's Law of Universal Gravitation, which uses a special number called the gravitational constant (G = 6.67 × 10⁻¹¹ N·m²/kg²). This gravitational pull also gives objects their Potential Energy based on their height above Earth.
What Affects Gravitational Force
Three things control how strong the gravitational force is between objects. First, the mass of the first object - more mass means stronger pull. Second, the mass of the second object - again, more mass creates stronger force. Third, the distance between the objects' centers - when objects are closer, the force is much stronger. In fact, if you double the distance, the force becomes four times weaker. When objects fall under gravity's influence, they gain speed and Kinetic Energy as they move.
Real-World Examples
Gravitational force keeps the Moon orbiting around Earth and Earth orbiting around the Sun. It holds our atmosphere in place and makes rain fall down instead of floating away. The force between Earth and the Moon creates ocean tides. Even