electrical Calculators
Last updated: May 2026
Ohm's Law Calculator
Solves for voltage, current, or resistance in a resistive circuit using V = I × R.
Electrical Power Calculator
Calculates electrical power in watts from voltage and current using P = V × I.
Wire Gauge Calculator
Determines the minimum copper wire gauge (AWG) needed to limit voltage drop in an electrical run.
Capacitive Reactance Calculator
Calculates capacitive reactance (Xc) for a capacitor in an AC circuit at a given frequency.
Inductive Reactance Calculator
Calculates inductive reactance (XL) for a coil or inductor in an AC circuit at a given frequency.
Electricity Cost Calculator
Estimate the monthly electricity cost of any appliance by entering its wattage, daily usage hours, and your utility rate.
Transformer Turns Ratio Calculator
Determine a transformer's turns ratio from its primary and secondary voltages in seconds.
Circuit Breaker Sizing Calculator
Find the correct circuit breaker rating for any electrical load by entering the full-load current and a safety factor.
LED Resistor Calculator
Calculate the exact current-limiting resistor value needed to safely power an LED from any supply voltage.
Three Phase Power Calculator
Compute the total real power delivered by a three-phase AC system from line voltage, line current, and power factor.
Ohm's Law & Power Calculator
Solve for voltage, current, resistance, or power in any DC circuit by entering just two known electrical values.
Wire Gauge & Ampacity Calculator
Determine the minimum wire cross-sectional area (in mm²) needed to safely carry a given current over a set distance without exceeding your allowed voltage drop.
Electrical Load Calculator
Compute the total electrical demand of a building by summing lighting, appliance, HVAC, and motor loads, then applying an NEC-compliant demand factor.
Power Factor Correction Capacitor Calculator
Find the exact capacitor size in µF needed to correct a lagging power factor to a target value in AC electrical systems.
Motor Full Load Current Calculator
Calculate the full load current (FLA) drawn by a single-phase or three-phase AC motor from its horsepower, voltage, efficiency, and power factor.
Transformer Sizing Calculator
Determine the required KVA rating for a transformer based on connected load, voltage levels, load factor, and future growth.
Conduit Fill Calculator
Calculate the percentage of conduit fill for a given wire gauge, wire count, and conduit size to ensure NEC compliance.
Electrical Energy Cost Calculator
Estimate monthly electricity costs for any device or facility by entering power consumption, daily run time, and utility rates including demand charges.
Short Circuit Current Calculator
Calculate the available short-circuit fault current at any point in a three-phase electrical system, accounting for transformer impedance and cable length.
Wire Size Calculator
Find the minimum wire cross-sectional area in circular mils needed to keep voltage drop within code limits for any DC or single-phase AC circuit.
Ohm's Law Calculator
Solve for voltage, current, resistance, or power in any DC circuit using Ohm's Law.
Solar Panel System Calculator
Estimate how many solar panels you need to cover your home's electricity usage based on your location's sun hours and panel specs.
Electrical Load Calculator
Determine the total electrical demand of a building and the minimum service panel size needed to support it safely.
Motor Starting Current Calculator
Calculate the full-load running current of a three-phase AC motor from its horsepower, voltage, and efficiency ratings.
Battery Backup Time Calculator
Find out how long a battery bank will power your equipment during an outage, given voltage, capacity, and inverter efficiency.
Conduit Fill Calculator
Determines the minimum conduit diameter needed for a given number and gauge of wires per NEC fill rules.
Power Factor Correction Calculator
Calculates the reactive power (kVAR) of capacitors needed to raise a facility's power factor to a target value.
Voltage Drop Calculator
Computes the voltage drop across a wire run given current, one-way distance, wire gauge, and conductor material.
Capacitor Energy Storage Calculator
Calculates the energy stored, charge held, or RC time constant for a capacitor given its capacitance, voltage, and series resistance.
LED Series Resistor Calculator
Finds the correct series resistor value and power rating to safely drive one or more LEDs in series from a given supply voltage.
Transformer Calculator
Determine the primary current draw of a transformer given its output voltage, output current, and efficiency.
Battery Runtime Calculator
Estimate how many hours a battery will power a device based on its capacity, discharge depth, and system efficiency.
Wire Ampacity Calculator
Find the safe current-carrying capacity of a copper or aluminum wire based on AWG size, ambient temperature, and number of bundled conductors.
Three Phase Power Calculator
Calculate the real output power (kW) of a three-phase electrical system from line voltage, line current, power factor, and efficiency.
Voltage Drop Calculator
Calculate the percentage voltage drop along a conductor run based on current, one-way distance, wire gauge, and system voltage.
Transformer Sizing Calculator
Determine the minimum transformer kVA rating needed for a given electrical load, accounting for demand factor, power factor, safety margin, and ambient temperature derating.
Electrical Panel Load Calculator
Estimate the total ampere demand on an electrical panel by applying NEC-style load factors to lighting, receptacle, appliance, and motor circuits, then check it against the panel's main breaker rating.
Short Circuit Current Calculator
Compute the available short-circuit current (ASCC) at a fault point downstream of a transformer, accounting for transformer impedance and cable impedance to the fault location.
Conduit Fill Calculator
Calculate the percentage of a conduit's interior cross-sectional area occupied by wires and check it against NEC fill limits.
Battery Bank Sizing Calculator
Calculate the total battery bank capacity in amp-hours (Ah) needed for off-grid solar systems or backup power, factoring in autonomy, depth of discharge, and system efficiency losses.
Ohm's Law Solver (V = IR)
Solves Ohm's Law for voltage, current, or resistance — pick the unknown and enter the other two values.
Capacitor Charge Time Calculator
Calculates how long a capacitor takes to charge fully through a resistor, using the RC time constant.