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.
How Levers Work: The Three Classes Explained
A lever is a rigid bar and a pivot — nothing more — yet it's the oldest force-multiplying machine we have. Here's the moment-balance math behind it, and how the three classes of lever differ.
Block and Tackle: How Pulleys Multiply Your Pulling Force
A single pulley just changes the direction you pull. Add a second, movable pulley and you start multiplying force — here's how counting rope segments tells you exactly how much.
Gear Ratios Explained: Trading Speed for Torque
Every meshed pair of gears is really a rotating lever, and the tooth-count ratio between them tells you exactly how much speed you're trading for torque, or vice versa.
Why Ramps Make Heavy Loads Easier to Move
An inclined plane doesn't reduce the work needed to lift a load — it spreads that work over a longer distance so the force required at any moment is smaller. Here's the math and the trade-offs.
The Physics of the Screw: From Archimedes to the Modern Bolt
A screw is an inclined plane wrapped around a cylinder, which is why a small turning effort can generate enormous clamping force — and why threads hold their position without slipping.
Archimedes and the Machines That Shaped Engineering
Long before 'mechanical advantage' had a name, Archimedes and later Leonardo da Vinci studied levers, pulleys, and gears closely enough to leave behind ideas engineers still use today.
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 →