GearLab
Precision engineering calculators for gearbox design, analysis & selection.
kW
RPM
→
—N·m
Engineering Calculators
Click any module to open the full calculator
Spur Gear Calculator
Module, teeth, pressure angle → full geometry: PCD, OD, root dia, center distance, contact ratio.
Helical Gear Calculator
Helix angle, normal/transverse module, lead, axial pitch and all helical geometry dimensions.
Power & Torque
Any 2 of kW / Torque / RPM → third. Tangential, radial, and axial gear forces.
Gear Ratio & Speed
Single, two-stage, three-stage, and planetary gear ratio. Output RPM at each stage.
Stress Analysis
Lewis bending stress and Hertz contact stress. Safety factor check against allowable.
Service Factor
AGMA application factor, shock load classification, and gearbox life expectancy estimator.
Unit Converter
Power, torque, speed, length, force, pressure — all engineering units in one place.
Engineering Guide
Reference formulas, standard module table, pressure angles, AGMA standards overview.
Quick Reference — Standard Modules (ISO 54)
<% for (const m of [1, 1.25, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10, 12, 16, 20]) { %>
<% } %>
Module (m) is the fundamental size parameter of a gear tooth. A larger module means larger, stronger teeth.
Standard modules follow a preferred number series — always select from this table for interchangeability.
Pitch Circle Diameter = m × z | Addendum = m | Whole Depth = 2.25m