How it works
Choose any object — a planet, a moon, or the orbit of one around another — as your reference size. Enter that object's size in centimeters and every other object in the list rescales proportionally, using each body's real equatorial diameter (or, for orbits, its real orbital distance). The math is a simple ratio: whatever scale your reference object is at, every other object is shown at that same scale.
Why use a scale calculator
It's easy to read that Jupiter is about 11 times wider than Earth, but much harder to picture. Scaling everything to an object you can hold — a marble, a basketball, a classroom globe — makes the size differences between planets, moons, and orbital distances immediately intuitive. This tool is handy for:
- Building a to-scale model of the solar system for a science fair or classroom
- Sizing 3D-printed or hand-made planet models consistently
- Teaching relative planetary and lunar sizes, or how far apart orbits really are
- Satisfying curiosity about just how small Earth is next to the Sun or the gas giants
What's included
Covers the Sun, all eight planets, Pluto, and their major moons (including Earth's Moon, the Galilean moons of Jupiter, Saturn's Titan, the large moons of Uranus and Neptune, and Pluto's moon Charon), plus the orbital distances of each planet and several major moons.