Educational electrical tools
Electrical calculators & reference tools
Calculate wire, power, energy cost, battery, solar, transformer, motor, and circuit relationships without an account or quote form.
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Wire & voltage
Conductor geometry, resistance, voltage drop, and voltage-drop-only selection.
Voltage Drop CalculatorCalculate resistive voltage drop, delivered voltage, conductor resistance, and I²R loss for DC, single-phase, or three-phase circuits.Wire Size by Voltage Drop CalculatorFind the smallest supported AWG conductor that meets your editable voltage-drop target using a transparent resistance model.AWG to mm² CalculatorConvert American Wire Gauge to diameter, cross-sectional area, and circular mils, or find the nearest AWG for a metric area.Wire Resistance CalculatorEstimate conductor resistance, resistance per length, voltage loss, and heat loss from material, size, length, and temperature.
Power & phase
DC, single-phase, three-phase, real, apparent, and reactive power relationships.
Watts to Amps CalculatorConvert watts to current for DC, single-phase AC, and three-phase AC with explicit power factor.Amps to Watts CalculatorConvert current to real power for DC, single-phase AC, and balanced three-phase AC.kW to Amps CalculatorConvert kilowatts to current for DC, single-phase, or balanced three-phase systems.kVA to Amps CalculatorConvert apparent power in kVA to current for single-phase or balanced three-phase systems.Single-Phase Power CalculatorCalculate real power, apparent power, and current for a single-phase AC circuit.Three-Phase Power CalculatorCalculate real and apparent power from line voltage, current, and power factor in a balanced three-phase system.Power Factor CalculatorCalculate power factor, reactive power, and phase angle from real and apparent power.
Battery, energy & solar
Energy cost and usage, battery runtime, bank layout, inverter loads, EV charging, and DC cable-loss planning.
Battery Runtime CalculatorEstimate ideal and adjusted runtime from battery energy, load, usable depth, and conversion efficiency.Battery Bank CalculatorCalculate series/parallel battery quantity, bank voltage, amp-hours, and watt-hours from unit specifications.Inverter Size CalculatorAggregate running and surge loads, then apply your own headroom and efficiency assumptions.Solar Cable Voltage Drop CalculatorCalculate resistive DC voltage drop and cable power loss between solar-system components.Electricity Cost CalculatorCalculate electricity cost from energy use, billing-period length, and your own price per kilowatt-hour.Appliance Running Cost CalculatorEstimate appliance energy use and operating cost from wattage, daily runtime, days, and your electricity rate.kWh CalculatorConvert watts and operating time into watt-hours and kilowatt-hours for one or more identical loads.EV Charging Cost CalculatorEstimate EV charging energy, time, and cost from battery capacity, charge change, efficiency, charger power, and your rate.Energy Usage CalculatorAdd multiple appliances to estimate daily and period energy use plus cost at your entered electricity rate.
Transformers & motors
Ideal transformer relationships, motor current estimates, and generator load aggregation.
Transformer kVA CalculatorCalculate transformer current from kVA and voltage for single-phase or balanced three-phase systems.Transformer Turns Ratio CalculatorCalculate ideal voltage, turns, and inverse current relationships between transformer windings.Motor Current EstimatorEstimate motor input current from mechanical output, voltage, phase, efficiency, and power factor.Generator Sizing & Load CalculatorSize a generator estimate from running and starting loads, then apply your own reserve and power-factor assumptions.
Technical utilities
Ohm's law, resistor networks, divider circuits, geometry, and LED resistor math.
Ohm's Law CalculatorSolve voltage, current, resistance, and power from any sufficient pair of electrical values.Voltage Divider CalculatorCalculate two-resistor divider output, current, and the effect of an optional load resistor.Series & Parallel Resistor CalculatorCalculate equivalent resistance and basic branch values for a supported series or parallel resistor network.Conduit Fill Geometry CalculatorCalculate geometric occupied area and fill percentage from user-entered raceway and conductor diameters.LED Resistor CalculatorCalculate a series resistor and resistor dissipation for a simple string of LEDs.
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Educational use
Results explain electrical math. They are not engineering, installation, or code-compliance advice.