Advanced calculator
Enter Gravity Values
Choose the unknown value. Enter the remaining values.
The tool converts units, solves the equation, and builds a chart.
Formula used
Newton's Universal Law of Gravitation
How to use this calculator
Step by Step Guide
- Select the unknown value from the solve menu.
- Enter both masses when force or distance is needed.
- Enter distance when force or mass is needed.
- Enter target force when solving a mass or distance.
- Pick matching units from each unit menu.
- Choose result precision and graph type.
- Press the calculate button.
- Download the result as CSV or PDF.
Example data table
Sample Gravity Calculations
| Case |
Mass 1 |
Mass 2 |
Distance |
Approximate Force |
| Earth pulling 1000 kg object |
5.9722e24 kg |
1000 kg |
6,371,000 m |
9.82e3 N |
| Earth and Moon |
5.9722e24 kg |
7.342e22 kg |
384,400 km |
1.98e20 N |
| Sun and Earth |
1.98847e30 kg |
5.9722e24 kg |
1 au |
3.54e22 N |
| Two lab spheres |
10 kg |
15 kg |
0.5 m |
4.00e-8 N |
Physics article
Understanding Gravitational Attraction
Newton's law of gravity explains attraction between two masses. Every object pulls every other object. The pull grows when either mass grows. The pull becomes weaker when distance grows. This simple rule helps describe falling objects, satellites, planets, tides, and many engineering estimates.
Why Distance Matters
Distance has a squared effect. If distance doubles, force becomes one fourth. If distance triples, force becomes one ninth. This inverse square relation is important. It explains why nearby bodies can create stronger local effects than distant bodies with large mass.
Using Correct Units
The standard equation works best in SI units. Mass should be in kilograms. Distance should be in meters. Force is then returned in newtons. This calculator accepts many common units. It converts them before solving the equation. That reduces manual errors.
Solving Unknown Values
Many problems ask for more than force. You may know force and distance. You may need one mass. You may know both masses and force. You may need separation distance. The same equation can be rearranged for each unknown. This page performs those rearrangements automatically.
Energy and Motion Clues
The result also includes potential energy, acceleration, orbital speed, and escape speed. These extra values add context. Potential energy is negative for a bound attractive system. Acceleration shows how strongly each body responds. Orbital speed estimates circular motion around mass one. Escape speed estimates the speed needed to leave that body's gravity field.
Practical Uses
Students can check homework. Teachers can build demonstrations. Science writers can compare astronomical cases. Engineers can make quick estimates for small body attraction. The chart is useful because it shows trends. Force rises linearly with mass. Force falls sharply with distance. This makes the law easier to understand.
Important Limits
This calculator uses classical gravity. It assumes point masses or spherical bodies measured from their centers. It is not designed for relativistic systems, irregular fields, or very high precision mission planning. For most classroom and general physics work, it gives clear and useful results.
FAQs
Frequently Asked Questions
What does Newton's law of gravity calculate?
It calculates the attractive force between two masses. The result depends on both masses, their center-to-center distance, and the gravitational constant.
Why must distance be center-to-center?
The formula treats objects as point masses or spherical bodies. For spheres, distance is measured from one center to the other center.
Can I solve for mass instead of force?
Yes. Select mass 1 or mass 2 as the unknown. Then enter force, distance, and the other known mass.
Can I use Earth or Sun masses?
Yes. The mass unit menu includes Earth mass, Moon mass, and solar mass for faster astronomy calculations.
Why is the force very small for lab objects?
Gravity is weak between ordinary objects. Large forces usually need huge masses, small distances, or both.
What is gravitational potential energy?
It is the stored energy from gravitational attraction. This calculator uses the common formula U equals negative G times both masses divided by distance.
What does the graph show?
The graph shows how force changes when distance, mass 1, or mass 2 is varied around the calculated value.
Is this suitable for advanced orbital missions?
No. It is best for education and general estimates. Mission planning needs detailed models, perturbations, and precise ephemeris data.