Gravitational Force Calculator

How to Use This Calculator

1. Enter mass 1 and mass 2 in kg, and the distance between their centers in meters.
2. Use Solar System Presets tab to get Earth-Moon, Earth-Sun, etc. forces instantly.
3. Professional tier adds gravitational potential energy, field strength, and tidal force.

Formula

Example

Frequently Asked Questions

• What is Newton's Law of Gravitation? ▼
  Newton's Law states that every mass attracts every other mass with a force F = G × m₁ × m₂ / r², where G = 6.67430×10⁻¹¹ N·m²/kg², m₁ and m₂ are the masses, and r is the distance between their centers.
• How is this different from F = ma? ▼
  F = ma (Newton's second law) gives force from acceleration. F = Gm₁m₂/r² gives the specific gravitational attractive force between two masses separated by distance r.
• What is the gravitational force between Earth and Moon? ▼
  With m₁ = 5.972×10²⁴ kg, m₂ = 7.346×10²² kg, r = 3.844×10⁸ m, F = 6.674×10⁻¹¹ × 5.972×10²⁴ × 7.346×10²² / (3.844×10⁸)² ≈ 1.98×10²⁰ N.
• What is gravitational potential energy? ▼
  Gravitational potential energy U = −Gm₁m₂/r. It is negative (bound system) and approaches zero as r → ∞. Energy released bringing objects from infinity to distance r equals |U|.
• What is tidal force? ▼
  Tidal force is the difference in gravitational pull across an extended object. It scales as F_tidal ∝ 2Gm₂r_body/r³, where r_body is the size of the object being stretched.

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