Electrical & Electronics Calculators

Voltage Calculator

Calculate voltage using Ohm's Law: V = I × R. Enter current and resistance to find voltage. Ideal for electronics students, hobbyists, and engineers designing or troubleshooting circuits with known current and resistance values.

Current Calculator

Calculate current using Ohm's Law: I = V / R. Enter voltage and resistance to find current. Perfect for analyzing circuit behavior, sizing protective devices, and understanding how voltage and resistance affect current flow in electrical systems.

Resistance Calculator

Calculate resistance using Ohm's Law: R = V / I. Enter voltage and current to find resistance. Essential for circuit design, component selection, and understanding how voltage and current determine the opposition to electron flow.

Power Calculator

Calculate electrical power using P = V × I. Enter voltage and current to find power in watts. Ideal for estimating energy usage, sizing power supplies, and understanding the relationship between voltage, current, and power consumption.

Electrical Power Calculator

Calculate electrical power using P = V × I. Enter voltage and current with unit conversions. Supports multiple unit conversions (V/kV, A/mA, W/kW) for flexible use in residential, automotive, and industrial electrical calculations.

Power from Resistance Calculator

Calculate electrical power using P = I^2 × R. Enter current and resistance to find power in watts. Uses P = I²R to calculate heat dissipation in resistors, wire losses, and power consumption when voltage is unknown.

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. Helps electricians, contractors, and DIYers select the correct wire gauge for safe electrical installations based on NEC ampacity guidelines.

Energy Consumption Calculator

Calculate energy consumption in kWh from power (W) and usage time, and estimate cost. Helps homeowners and businesses estimate appliance energy usage, track electricity consumption, and identify opportunities for energy savings.

Electricity Bill Calculator

Estimate monthly electricity bill based on appliance usage, tiers and rates. Helps consumers estimate monthly costs, compare rate plans, and understand how appliance usage affects their electricity bill.

Voltage Divider Calculator - Output Voltage

Calculate the output voltage of a voltage divider circuit. Free tool for computing Vout from Vin and resistor values with step-by-step formula.

Series Resistor Calculator - Total Resistance

Calculate the total equivalent resistance of multiple resistors connected in series. Includes formulas, examples, and step-by-step calculations.

Parallel Resistor Calculator - Equivalent Resistance

Quickly compute the equivalent resistance of resistors in parallel. Supports up to multiple resistors with step-by-step formula explanation.

Current Divider Calculator - Branch Currents

Calculate the exact current flowing through parallel branches in a circuit. Uses the current divider rule to compute I1 and I2.

Kirchhoff Law Calculator

Simple KCL/KVL solver for small linear circuits (sum of currents/voltage loops). Helps electrical engineering students and circuit designers verify node and loop equations for complex multi-branch circuits.

Resistor Color Code Calculator

Decode 4-band resistor color codes, calculate resistance, multiplier and tolerance. Perfect for electronics students, hobbyists, and technicians who need to quickly identify resistor values without memorizing the complete color code chart.

Capacitor Charge Calculator - Q=CV

Quickly calculate the charge stored in a capacitor. Uses the formula Q = C × V. Perfect for electronics students and engineers.

Capacitor Energy Calculator (Joules)

Calculate the energy stored in a capacitor in Joules. Uses the E = ½CV² formula for accurate electrical energy computation.

RC Time Constant Calculator - Charge Time

Calculate the RC time constant (tau) for resistor-capacitor circuits. Discover how long it takes to charge or discharge a capacitor.

RL Time Constant Calculator (Tau)

Calculate the RL time constant for inductor-resistor circuits. Find out how fast current stabilizes in inductive loads with this free tool.

Inductive Reactance Calculator (XL)

Calculate inductive reactance (XL) using the 2πfL formula. Determine an inductor's AC impedance based on frequency with this free online tool.

Capacitive Reactance Calculator (XC)

Calculate capacitive reactance (XC) at a specific AC frequency. Free tool for computing capacitor impedance using 1/(2πfC).

Power Factor Calculator

Compute power factor from P, S or impedance phase angle. Essential for industrial facility managers, electrical engineers, and energy auditors to assess electrical system efficiency and identify correction needs.

Three Phase Power Calculator

Calculate three-phase real and apparent power for balanced loads. Designed for industrial electricians, engineers, and facility managers sizing equipment for balanced three-phase electrical systems common in commercial buildings.

Transformer Calculator

Calculate turns ratio, primary/secondary voltages and currents for ideal transformers. Essential for electrical engineers, technicians, and hobbyists designing power supplies, matching transformer specs, or understanding voltage conversion ratios.

Motor Current Calculator

Estimate motor current from power rating, voltage and efficiency. Helps electricians and engineers size circuit breakers, contactors, cables, and motor starters based on full-load current ratings.

Battery Life Calculator

Estimate battery runtime: runtime = capacity (Ah) × voltage / load (W). Essential for product designers, IoT developers, and consumers comparing battery performance across devices, brands, and usage scenarios.

Battery Charging Time Calculator

Estimate charging time from capacity and charger current considering efficiency. Useful for EV owners, battery technicians, and anyone using rechargeable batteries to plan charging schedules and understand charging losses.

UPS Backup Time Calculator

Estimate UPS backup time from battery bank capacity and load. Helps data center managers, IT professionals, and homeowners size UPS systems for critical equipment and ensure adequate runtime during power outages.

Solar Panel Calculator

Estimate solar panel array size from daily energy demand and insolation. Helps homeowners, installers, and renewable energy enthusiasts size solar arrays based on daily consumption, location sunlight, and panel specifications.

Buck Converter Calculator

Estimate output voltage/current for ideal buck converter Vout = D × Vin. Perfect for power electronics engineers, hobbyists, and students designing efficient voltage step-down circuits for battery-powered devices.

Boost Converter Calculator

Estimate output voltage for ideal boost converter Vout = Vin / (1 - D). Ideal for designing voltage step-up circuits in battery-powered devices, renewable energy systems, and LED driver applications.

PWM Duty Cycle Calculator

Compute duty cycle from high time and period or required average voltage. Useful for robotics engineers, electronics hobbyists, and embedded systems developers working with motor control and LED dimming circuits.

Electrical Unit Converter

Convert between common electrical units: V, mV, kV, A, mA, W, kW, etc. Quickly switch between volts, millivolts, kilovolts, amps, milliamps, watts, and kilowatts for electrical engineering and electronics work.