Electrical Conversion and Formula Tools

Fast single-task tools for common U.S. electrical work, including unit conversions, power formulas, conductor references, conduit layout, and field documentation checks.

Shunt Resistor

Size a DC current shunt from full-scale current and rated millivolt drop.

Insulation Resistance Correction

Correct megger readings to a reference temperature for maintenance records and trend review.

4 Point Saddle Bend

Lay out four marks, bend spacing, flat section width, and shrinkage for a conduit saddle.

3 Point Saddle Bend

Calculate center and outer bend marks for a peaked conduit saddle over a narrow obstacle.

Offset Bend Multiplier

Find the bend multiplier and mark spacing for a simple conduit offset.

Offset Bend Shrink

Estimate shrink allowance for a simple conduit offset.

Offset Bend Spacing

Calculate spacing between conduit offset bend marks.

Kick Bend Multiplier

Calculate field multiplier spacing for a conduit kick bend.

Kick Bend Shrink

Estimate shrink adjustment for a conduit kick bend.

Rolling Offset Travel

Calculate true diagonal travel and roll angle for a conduit rolling offset.

Parallel Offset Spacing

Calculate mark spacing and second mark from true offset and bend angle.

Watts and Amps

Convert watts and amps from voltage, phase, and power factor.

kW and amps

Convert kW and amps for single-phase and three-phase AC loads.

Voltage, Current, and Resistance

Solve one Ohm law variable from the other two.

kVA and Amps

Convert apparent power and current for single-phase and three-phase systems.

Power Factor, kW, and kVA

Solve one value from the kW, kVA, and power factor relationship.

AWG and mm2

Convert AWG and approximate square millimeter conductor area.

kcmil and mm2

Convert large-conductor area between kcmil and square millimeters.

Voltage drop percent

Convert dropped volts and percent voltage drop.

AWG Diameter

Convert AWG gauge to bare conductor diameter.

Wire Resistance

Estimate copper or aluminum conductor resistance.

Temperature Resistance

Correct conductor resistance for temperature.

Voltage Drop Volts

Estimate dropped volts from current, length, and resistance.

Max Wire Run

Estimate maximum run length for a voltage-drop target.

Horsepower and amps

Estimate motor current from horsepower and operating assumptions.

Horsepower and kW

Convert motor horsepower and kilowatts.

Electricity cost

Multiply kWh by an electricity rate.

Watts and kWh

Convert power, runtime, and energy usage.

Battery Ah and Wh

Convert battery amp-hours and watt-hours.

EV amps and kW

Convert EV charging current and power.

Impedance and Current

Calculate current or voltage from impedance magnitude.

RC Time Constant

Calculate tau for resistor-capacitor circuits.

Voltage Divider Output

Calculate Vout from Vin, R1, and R2.

Current Divider Ratio

Calculate current split in two parallel branches.

Series and Parallel Resistance

Calculate total resistance for two-resistor networks.

Capacitive Reactance

Calculate Xc from capacitance and frequency.

Inductive Reactance

Calculate XL from frequency and inductance.

RL Time Constant

Calculate tau for inductor-resistor circuits.