Gravitational Force Calculator
Newton’s law of universal gravitation estimates the attractive force between two masses separated by a center-to-center distance.
How to use this calculator
- Enter both masses in kilograms and the distance between their centres in metres.
- Check the labels and units before applying the result to a real task.
- Change one input at a time when comparing scenarios.
Formula and method
F = Gm₁m₂/r², where G ≈ 6.67430×10⁻¹¹ N·m²/kg²
- F = Gm₁m₂/r², where G ≈ 6.67430×10⁻¹¹ N·m²/kg²
- The simple formula treats objects as point masses or spherically symmetric bodies and uses Newtonian gravity.
Worked examples
Worked example
Two 1 kg masses are separated by 1 metre.
F = 6.67430×10⁻¹¹×1×1/1² ≈ 6.67430×10⁻¹¹ N.
F = 6.67430×10⁻¹¹×1×1/1² ≈ 6.67430×10⁻¹¹ N.
Understanding the result
Newton’s law of universal gravitation estimates the attractive force between two masses separated by a center-to-center distance.
The simple formula treats objects as point masses or spherically symmetric bodies and uses Newtonian gravity.
Important notes
The simple formula treats objects as point masses or spherically symmetric bodies and uses Newtonian gravity.
Displayed values are rounded for readability; retain appropriate precision when continuing a calculation.
Frequently asked questions
Why is the force between everyday objects so small?
The gravitational constant is extremely small, so ordinary laboratory-scale masses exert tiny mutual gravitational forces.
Does doubling distance halve gravity?
No. The inverse-square relationship means doubling the distance reduces force to one quarter when masses stay fixed.
Does the tool calculate weight on Earth?
It calculates the mutual force between two entered masses. Near Earth, weight is usually estimated using mass times local gravitational acceleration.
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Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.