Free gravitational force calculator using Newton's Law of Universal Gravitation. Calculate force between masses, surface gravity, escape velocity, and orbital velocity for planets and celestial bodies.
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Our gravitational force calculator applies Newton's Law of Universal Gravitation to compute attractive force between any two masses. Calculate gravitational force, surface gravity, escape velocity, and orbital velocity for planets, moons, and celestial bodies. Get instant results with step-by-step calculations.
Gravitational force is the attractive force between any two objects with mass. Discovered by Sir Isaac Newton in 1687, this universal force governs everything from falling apples to orbiting planets. The force depends on both masses and decreases with the square of the distance between them.
Newton's Law of Universal Gravitation
F = G x m1 x m2 / r2 where G=6.674x10-11 m3/kg/s2Calculate gravitational force, mass, distance, surface gravity, escape velocity, or orbital velocity.
Instant calculations for Earth, Moon, Mars, Jupiter, and Sun using accurate astronomical data.
Support for kilograms, Earth masses, Solar masses, meters, kilometers, AU, and more.
See complete derivations with formulas and scientific notation for large numbers.
Calculate gravitational effects between planets, stars, and other celestial bodies.
Determine escape velocities and orbital parameters for spacecraft trajectories.
Solve Newton's Law of Universal Gravitation problems for coursework and exams.
Compare surface gravity and escape velocities across different planets and moons.
The gravitational constant G = 6.67430 x 10-11 m3/kg/s2 is a fundamental physical constant that determines the strength of gravitational attraction. It was first measured by Henry Cavendish in 1798.
The gravitational constant is extremely small, making gravity roughly 10^36 times weaker than electromagnetism. Gravity only becomes significant with very large masses like planets and stars.
Escape velocity is the minimum speed needed to escape a celestial body's gravitational field without further propulsion. For Earth, it's about 11.2 km/s (25,000 mph). The formula is v = sqrt(2GM/r).
Gravitational force follows an inverse-square law: doubling the distance reduces the force to 1/4, tripling reduces it to 1/9, and so on. This is why gravity weakens rapidly with distance.
Surface gravity (g = GM/r2) is the gravitational acceleration at a body's surface, measured in m/s2. Gravitational force (F = GMm/r2) is the actual force between two masses, measured in Newtons.
Astronauts appear weightless because they're in continuous free fall around Earth. The ISS experiences about 90% of Earth's surface gravity, but everything inside is falling together, creating the sensation of weightlessness.