Engineering

Free American Wire Gauge (AWG) calculator — look up wire diameter, cross-sectional area, and resistance; size wires by current and voltage drop; convert diameters to AWG; and calculate equivalent gauge for parallel wires.

Free American Wire Gauge (AWG) wire size reference table and calculator. Look up wire diameter, cross-sectional area, resistance, ampacity, skin depth, and breaking force for AWG 4/0 through AWG 40. Supports copper, aluminum, and 6 other materials.

Free electricity bill calculator — estimate your monthly electricity costs by appliance, calculate bills from meter readings, compare electricity rates, and track annual CO2 emissions.

Free Gear Ratio Calculator — compute output RPM, torque multiplication, mechanical advantage, and power for single-stage, multi-stage compound gear trains, or back-calculate the ratio from known speeds.

Free Horsepower (HP) calculator — convert torque and RPM to HP, solve for torque or RPM, convert between HP/kW/PS, estimate quarter-mile performance, and calculate electrical or hydraulic horsepower. Eight calculation modes in one tool.

Free Parallel Resistor Calculator — instantly find equivalent resistance for any number of resistors connected in parallel. Supports mixed units (µΩ to GΩ), missing-resistor solver, series mode, step-by-step breakdown, conductance, current distribution, and power dissipation.

Free Resistor Calculator — decode resistor color codes (3, 4, 5, and 6-band), calculate series and parallel resistance, solve voltage divider circuits, and decode SMD resistor codes. Includes a visual resistor diagram and IEC 60062 color band reference chart.

Free Resistor Color Code Chart and Calculator — decode 3-band, 4-band, 5-band, and 6-band resistors instantly. Includes reverse lookup, parallel/series calculator, SMD decoder, and full IEC 60062 reference table.

Free Torque Calculator — compute rotational force (torque) using τ = F × r × sin(θ), convert between N·m, lb·ft, lb·in, and kgf·cm, solve Power–Torque–RPM relationships, and calculate bolt clamping torque with lubrication factors.