Precision · Engineering · Physics
From gear ratios to fluid dynamics — engineering-grade calculators built for accuracy. Free, fast, and browser-native.
The Suite
Engineering, physics, and geometry calculators — all free, all in your browser, all peer-reviewed for accuracy.
Calculate mechanical advantage, output torque, and speed ratios for any gear configuration. Essential for transmission design.
Open Tool →Determine rotational force across mechanical systems. Covers lever arms, angular momentum, and moment calculations.
Open Tool →Kinematics solved instantly. Find velocity, acceleration, displacement, or time from any set of known values.
Open Tool →Surface area for circles, polygons, ellipses, spheres, and composite shapes. Supports metric and imperial.
Open Tool →Calculate helix angle, normal pitch, and strength parameters for helical gear sets used in high-load transmissions.
Open Tool →Solve complex planetary gearbox ratios — sun, planet, and ring gear configurations including compound epicyclic systems.
Open Tool →Try It Now
Enter your driver and driven gear teeth counts. Results calculate instantly.
The gear ratio is simply the relationship between the number of teeth on two meshing gears. A large driven gear relative to the driver gear creates a reduction — slowing speed but multiplying torque.
Formula: Gear Ratio = Driven Teeth ÷ Driver Teeth
Example
A 20-tooth driver gear meshing with a 60-tooth driven gear produces a 3:1 ratio — the output shaft turns 3× slower but with 3× more torque.
Every formula on CalcSphere is peer-reviewed against engineering textbooks and SI standards. We don't estimate — we calculate.
All calculators run entirely in your browser. No server calls, no tracking, no paywalls — just instant, private calculation.
Used by mechanical engineers, students, and hobbyists to design transmissions, power systems, and mechanical linkages.
Switch between metric (SI) and imperial units instantly. All major physical quantities supported with automatic conversion.
Aesthetic Reference
The cinematic reference driving this site's visual identity — sophisticated momentum, warm rhythm, and kinetic precision.