LEVERLAB
How things move — simple machines, mechanics, and hands-on STEM.
From finding a lever’s mechanical advantage and a pulley system’s effort force to working out a gear ratio, a ramp’s force, a wheel-and-axle’s torque, and a screw’s mechanical advantage, LeverLab pairs free hands-on calculators with clear, worked-example guides and a richly illustrated museum. See the physics, then feel it.
Simple Machine Calculators
Free tools for every simple machine — lever mechanical advantage, pulley mechanical advantage, gear ratio, inclined plane force, wheel & axle torque, and screw mechanical advantage.
Lever Calculator
Find a lever's mechanical advantage and the effort force needed to lift a load, from the effort and load arm lengths measured from the fulcrum
Pulley Calculator
Find a pulley system's mechanical advantage and effort force from the number of supporting rope segments, with an optional efficiency figure
Gear Ratio Calculator
Turn a pair of gear tooth counts into a gear ratio, and see the resulting output speed and torque if you supply an input
Inclined Plane Calculator
Find a ramp's mechanical advantage, angle, and the force needed to push a load up it, with an optional friction coefficient
Wheel & Axle Calculator
Convert an effort force applied at a wheel's rim into the load it can turn at the axle, plus the resulting torque
Screw Calculator
Find a screw's mechanical advantage from the turning lever-arm length and the screw's pitch, plus the effort force needed
Museum of Simple Machines
Wander an immersive museum of the devices and thinkers behind everyday mechanics — levers and pulleys, wheels, gears and axles, inclined planes, wedges and screws, and the historic machines and inventors, from Archimedes to Leonardo da Vinci, who first worked out how they trade force for distance, each in its own gallery, so you can get to know the stories behind every mechanism: how it was discovered, what makes it work, and where it still shows up in the tools and machines around you.
Tour the museum →From the Journal
Fresh guides on levers, pulleys, gears, inclined planes, and screws, plus the history of mechanics and practical tips for DIY and engineering projects.
Wheel and Axle: The Rotating Lever Behind Doorknobs, Steering Wheels, and Winches
A doorknob, a screwdriver, a steering wheel, and a capstan are all the same machine: a lever whose fulcrum sits at the center of a circle instead of along a straight bar. Here's the wheel-radius-over-axle-radius math behind all of them.
Designing a Simple Machine to Hit a Target Mechanical Advantage
Predicting a machine's mechanical advantage from its dimensions is arithmetic. Designing dimensions to hit a target MA reverses the problem — here's the method for all six machines, worked to MA 4, plus why you must verify the rounded, buildable version.
Mechanical Advantage vs. Efficiency: Why No Real Machine Hits Ideal
Mechanical advantage describes a machine's geometry. Efficiency describes what friction takes back once that geometry meets the real world. Here's why a screw loses the most, a lever loses the least, and where the missing effort actually goes.
Choosing a Gear Ratio for Speed or Torque
Winches want torque; fans want speed. Here's how to work backward from what a job actually needs to a gear ratio — and real tooth counts — including when a multi-stage gear train beats one oversized pair.
Pulley Mechanical Advantage: It's the Rope Segments, Not the Pulleys
Count the pulley wheels and you'll often get the wrong answer. A pulley system's mechanical advantage is the number of rope segments actually supporting the load — here's the counting method, named rigging patterns, and a quiz that catches the common mistake.
Ramp Length vs. Effort: Where Friction Eats the Gains
Doubling a ramp's length always halves the ideal force — but not the force you'll actually feel. Here's the diminishing-returns curve friction puts on ramp length, and how to find the shortest ramp that actually meets your target effort.
Keep Learning
Plain-language explainers on how levers, pulleys, gears, inclined planes, and screws work, the historic figures who studied them, and the everyday mechanisms built from them — everything you need to dig deeper into the physics of simple machines.
Visit the Learn hub →