Every formula in the calculator has a story. These plain-language explanations cover what each equation means, where it comes from, and how to use it — each one with a worked example you can reproduce in the calculator.
Why every object with mass pulls on every other, and where the inverse-square law comes from.
The energy of motion, the origin of the one-half factor, and why speed matters more than mass.
How electric charges attract and repel — gravity's far stronger electrical cousin.
What E = mc² really says about the deep relationship between mass and energy.
More guides are added regularly. Have a formula you'd like explained? Let us know.