About LeverLab

Simple machines are the six basic devices — the lever, the pulley, the wheel and axle, the inclined plane, the wedge, and the screw — that every more complicated mechanism is ultimately built from. They show up everywhere: a crowbar prying a nail, a flagpole pulley, a bicycle’s gears, a loading ramp, an axe splitting wood, a screw jack lifting a car. Understanding how each one trades force for distance is one of the clearest, most hands-on entry points into physics, and it is exactly what LeverLab is built around.

Instead of long chapters you have to read end to end, the site is built around a set of small, single-purpose calculators, each aimed at one simple machine. The Lever Calculator works out the mechanical advantage of a lever from the effort and load arm lengths and the effort force needed to lift a given load. The Pulley Calculator takes the number of rope segments supporting the load and an optional efficiency figure to give the ideal and actual effort force. The Gear Ratio Calculator turns a pair of tooth counts into a gear ratio and, if you supply an input speed or torque, the resulting output speed and torque. The Inclined Plane Calculator finds the mechanical advantage and the force needed to push a load up a ramp of a given length and height, with an optional friction coefficient. The Wheel & Axle Calculatorconverts an effort force applied at a wheel’s rim into the load it can turn at the axle, plus the resulting torque. And the Screw Calculatorworks out the mechanical advantage of a screw from the turning lever-arm length and the screw’s pitch.

Beyond the calculators, the blog and learnsection explain the physics behind the numbers — mechanical advantage, effort and load, torque, and friction — in plain language, and the Museum of Simple Machines is a browsable collection of the devices and the historic figures who studied them, with every entry, image, and fact drawn from Wikipedia and Wikimedia Commons.

A few things worth stating plainly. LeverLab is an independent, educational site, not affiliated with any school, curriculum publisher, or manufacturer of tools or machines. It is supported by advertising, which is how the calculators stay free with no account required. Every result the tools produce — a mechanical advantage, an effort force, a gear ratio, a torque figure — is an estimate based on the idealized, frictionless physics taught in an introductory course, plus whatever efficiency or friction figure you choose to enter; it is not a substitute for measuring a real machine or for professional engineering calculations where safety or load limits are involved. If something looks off in a tool or an article, or you think a calculator is missing that would help, the contact page is the place to say so.