Circuits And Components
Series circuits, parallel circuits, shunts, and component calculation workflows.
Electrical Calculators
Find calculator pages by field task, formula, or reference workflow.
Calculator Categories
Categories group calculators by field workflow and reference context.
Commercial And Industrial Loads
Three-phase load balance, feeder, panel schedule, and commercial load estimate workflows.
Conduit Bending
Saddle, offset, kick, segment, rolling offset, and multiplier workflows for field conduit layout.
Lighting
Lumens, footcandles, fixture count, and lighting energy estimate workflows.
Motors And Starters
Motor current, full-load current, starting current, power, and starter sizing workflows.
Power Quality And Transformers
Transformer kVA, transformer current, generator sizing, and power-quality support workflows.
Power, Energy And Cost
Power factor, reactive power, energy use, and electricity-cost estimate workflows.
Residential Load And Service
Dwelling load, panel load, service size, and NEC 220 demand workflows.
Solar And Backup Power
Battery capacity, runtime, inverter, generator support, solar, backup, and EV charging estimate workflows.
Testing, Protection And Grounding
Insulation resistance, short-circuit current, pull-box sizing, grounding, and protection workflows.
Voltage, Current And Resistance
Ohm law, watts, amps, volts, resistance, and direct electrical formula workflows.
Wire, Raceway And Ampacity
Wire sizing, ampacity, derating, conduit fill, and raceway checks.
Available Calculators
Published calculator workflows ready to use.
Parallel Circuit Calculator
Use this simple fixed-resistance, DC-style Ohm law parallel circuit calculator for concept checks, worksheets, and preliminary component arithmetic. It is not AC impedance analysis, not component selection, and not an installation or code-compliance result.
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Motor Starting Current Calculator
Use full-load current and a user-selected starting multiplier to screen motor starting current before checking nameplate, controller, utility, and manufacturer data. This is not locked-rotor current, not a NEMA code-letter conversion, and not a starter selection.
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Motor Starter Current Reference Calculator
Enter motor nameplate FLA and transparent project assumptions to estimate starting current, an overload reference current, and a starter continuous-current discussion basis. This tool is not a starter selection, not an overload setting, and does not select a compliant starter, overload relay, breaker, conductor, disconnect, controller, SCCR, or equipment rating.
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Motor Power From Current Calculator
Enter line current, system voltage, phase count, power factor, and motor efficiency to create a transparent U.S. English current-to-power estimate. This calculator is not a full-load-current lookup, not a motor-nameplate substitute, does not reproduce NEC motor tables, does not apply NEMA design or code-letter data, does not select equipment, and does not verify code compliance.
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Insulation Resistance Calculator
Use a measured insulation resistance value, temperature correction factor, test voltage, duration, and entered screening reference to create a conservative testing worksheet estimate. It is not a pass/fail acceptance result, not safety clearance, and not code-compliance.
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Motor Current Calculator
Enter motor horsepower, voltage, phase count, efficiency, and power factor to create a transparent U.S. English preliminary motor running-current estimate. The model uses 746 watts per mechanical horsepower and does not reproduce NEC motor tables, replace a full-load-current table lookup, or select a compliant conductor, starter, overload setting, or overcurrent device.
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Full-Load Current Estimate Calculator
Enter motor horsepower, system voltage, phase count, efficiency, and power factor to create a transparent U.S. English arithmetic full-load-current estimate. This calculator is not a table lookup, does not reproduce NEC motor full-load-current tables, does not apply a Table 430.250 value, does not replace nameplate current, and does not select a code-compliant conductor, breaker, starter, or motor overload setting.
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Demand Factor Estimate (NEC 220 Context)
Use user-defined load blocks and demand-factor percentages to create a transparent U.S. English preliminary estimate. NEC 220 is retained as legacy and topical search context; current NEC load-calculation numbering, including Article 120/220 context, must be verified against the adopted edition. This calculator does not reproduce NEC tables, dwelling-unit rules, or any adopted code calculation.
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Electrical Load Calculator
Enter line voltage, phase count, load current, power factor, and utilization percentage to create a transparent U.S. English preliminary electrical-load estimate for motors and related equipment planning. For balanced three-phase input, line voltage means line-to-line voltage. The utilization percentage scales the entered load current before power is estimated.
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Wire Size Calculator
Enter the load current, one-way length, system voltage, allowable voltage-drop percentage, and conductor resistance per 1000 ft to estimate circuit voltage drop. The result is a preliminary engineering estimate and does not select an AWG/kcmil size or NEC wire size.
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Wire Derating Calculator
Enter a base ampacity and transparent user-supplied decimal multipliers for ambient temperature and bundling to estimate adjusted ampacity. Conductor count is a review flag only and does not automatically select a bundling factor. This calculator does not select or reproduce source tables.
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Segment Bend Calculator
Use total bend angle, number of segment bends, desired radius, and a start mark to lay out equal segment bend marks.
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