Gravitational Force Calculator
Calculate gravitational force between two objects using Newton's Law.
🌍 Physics📐 F = G × m1 × m2 / r²
Mass 1 (kg)
Mass 2 (kg)
Distance between centers (m)
Please enter valid values.
Formula & Reference
| Variable | Formula | Units |
|---|---|---|
| Gravitational Force Calculator | F = G × m1 × m2 / r² | Newtons |
Step-by-Step Examples
Example 1
Person on Earth
Earth 5.97e24 kg, person 70 kg, radius 6.37e6 m.
- F ≈ 686.7 N = weight force
- Equals mass × g = 70 × 9.81
✓ ~687 N
Example 2
Moon-Earth
Moon 7.35e22 kg, Earth 5.97e24 kg, distance 3.84e8 m.
- F = 1.99e20 N — causes tides!
✓ 1.99×10²⁰ N
Example 3
Two 1kg Objects
1 kg, 1 kg, 1 m apart.
- F = 6.674e-11 N — gravity is incredibly weak!
✓ 6.674×10⁻¹¹ N
Real-World Applications
Physics Students
Master Newton's law of gravitation.
Astronomers
Calculate gravitational forces between celestial bodies.
Teachers
Demonstrate gravity calculations in class.
Engineers
Apply gravitational calculations in orbital mechanics.
Common Mistakes to Avoid
⚠️
Confusing mass and weight
Mass = kg, weight = Newtons. F = mg where g = 9.81 m/s² on Earth.
⚠️
Wrong distance units
Distance must be in meters. Earth radius = 6.371×10⁶ m.
Frequently Asked Questions
What is G? ▾
6.674×10⁻¹¹ N·m²/kg² — one of nature's fundamental constants.
Why is gravity so weak? ▾
It's the weakest of the four fundamental forces. A small magnet lifts a paperclip against all of Earth's gravity.
How does gravity decrease with distance? ▾
Inverse square law: double the distance = 1/4 the force.