Electrical & Electronics Calculators
Free electrical and electronics calculators for Ohm's Law, power, circuits, transformers, batteries, solar, converters, and more.
Voltage Calculator
Calculate voltage using Ohm's Law: V = I × R. Enter current and resistance to find voltage.
Current Calculator
Calculate current using Ohm's Law: I = V / R. Enter voltage and resistance to find current.
Resistance Calculator
Calculate resistance using Ohm's Law: R = V / I. Enter voltage and current to find resistance.
Power Calculator
Calculate electrical power using P = V × I. Enter voltage and current to find power in watts.
Electrical Power Calculator
Calculate electrical power using P = V × I. Enter voltage and current with unit conversions.
Power from Resistance Calculator
Calculate electrical power using P = I^2 × R. Enter current and resistance to find power in watts.
Voltage Drop Calculator
Estimate voltage drop across a conductor using Vdrop = I × R(line) or using length, resistivity and conductor cross-section.
Wire Size Calculator
Estimate required conductor cross-sectional area or AWG based on current carrying and allowable voltage drop.
Energy Consumption Calculator
Calculate energy consumption in kWh from power (W) and usage time, and estimate cost.
Electricity Bill Calculator
Estimate monthly electricity bill based on appliance usage, tiers and rates.
Voltage Divider Calculator
Compute output voltage of a voltage divider (Vout = Vin × R2/(R1+R2)).
Series Resistor Calculator
Sum resistances in series (R = R1 + R2 + ...).
Parallel Resistor Calculator
Compute equivalent resistance for resistors in parallel.
Current Divider Calculator
Compute current distribution in parallel resistors.
Kirchhoff Law Calculator
Simple KCL/KVL solver for small linear circuits (sum of currents/voltage loops).
Resistor Color Code Calculator
Decode 4-band resistor color codes, calculate resistance, multiplier and tolerance.
Capacitor Charge Calculator
Calculate charge on capacitor Q = C × V.
Capacitor Energy Calculator
Compute energy stored in a capacitor: E = 0.5 × C × V^2.
RC Time Constant Calculator
Calculate tau = R × C and charging/discharging behavior.
RL Time Constant Calculator
Calculate tau = L / R for RL circuits.
Inductive Reactance Calculator
Compute XL = 2Ï€fL.
Capacitive Reactance Calculator
Compute XC = 1 / (2Ï€fC).
Power Factor Calculator
Compute power factor from P, S or impedance phase angle.
Three Phase Power Calculator
Calculate three-phase real and apparent power for balanced loads.
Transformer Calculator
Calculate turns ratio, primary/secondary voltages and currents for ideal transformers.
Motor Current Calculator
Estimate motor current from power rating, voltage and efficiency.
Battery Life Calculator
Estimate battery runtime: runtime = capacity (Ah) × voltage / load (W).
Battery Charging Time Calculator
Estimate charging time from capacity and charger current considering efficiency.
UPS Backup Time Calculator
Estimate UPS backup time from battery bank capacity and load.
Solar Panel Calculator
Estimate solar panel array size from daily energy demand and insolation.
Buck Converter Calculator
Estimate output voltage/current for ideal buck converter Vout = D × Vin.
Boost Converter Calculator
Estimate output voltage for ideal boost converter Vout = Vin / (1 - D).
PWM Duty Cycle Calculator
Compute duty cycle from high time and period or required average voltage.
Electrical Unit Converter
Convert between common electrical units: V, mV, kV, A, mA, W, kW, etc.