© 2026 CalConvs
Electricity Converters
Convert volts, amps, ohms, coulombs, and more. Quick, clear conversions for study, work, and DIY.
Charge
Convert between 17 different charge units instantly.
Linear Charge Density
Convert between 6 different linear charge density units instantly.
Surface Charge Density
Convert between 6 different surface charge density units instantly.
Volume Charge Density
Convert between 6 different volume charge density units instantly.
Current
Convert between 10 different current units instantly.
Linear Current Density
Convert between 8 different linear current density units instantly.
Surface Current Density
Convert between 6 different surface current density units instantly.
Electric Field Strength
Convert between 13 different electric field strength units instantly.
Electric Potential
Convert between 6 different electric potential units instantly.
Electric Resistance
Convert between 10 different electric resistance units instantly.
Electric Resistivity
Convert between 8 different electric resistivity units instantly.
Electric Conductance
Convert between 12 different electric conductance units instantly.
Electric Conductivity
Convert between 8 different electric conductivity units instantly.
Electrostatic Capacitance
Convert between 22 different electrostatic capacitance units instantly.
Inductance
Convert between 22 different inductance units instantly.
Electricity Engineering Calculators
Ohm's Law, power factor, solar, cable sizing & more — 35 free tools
Ohm's Law Calculator
Calculate voltage, current, or resistance using Ohm's Law (V = IR).
Electrical Power Calculator
Calculate electrical power in watts from voltage, current, and resistance.
Voltage Divider Calculator
Calculate output voltage of a resistor voltage divider circuit.
Series & Parallel Resistor Calculator
Calculate total resistance of resistors in series or parallel configurations.
Battery Life Calculator
Estimate how long a battery will last based on capacity and load current.
Battery Watt-Hours Calculator
Convert battery capacity from amp-hours to watt-hours and find runtime.
Electricity Bill Calculator
Calculate your monthly electricity bill based on appliance usage and tariff.
Generator Size Calculator
Determine the right generator size (kVA/kW) for your power needs.
UPS Battery Backup Calculator
Calculate UPS battery backup time for your connected devices.
Ampere to Watt Calculator
Convert amperes to watts using voltage, or watts to amperes.
Capacitor Charge Time Calculator
Calculate capacitor charge/discharge time using the RC time constant.
Inductor Reactance Calculator
Calculate inductive reactance (XL) at any frequency for an inductor.
LED Resistor Calculator
Calculate the correct current-limiting resistor value for an LED circuit.
Capacitor Energy Storage Calculator
Calculate the energy stored in a capacitor from capacitance and voltage.
Resonant Frequency Calculator
Calculate the resonant frequency of an LC circuit.
RC Low Pass Filter Calculator
Calculate the cutoff frequency and response of an RC low-pass filter.
Wheatstone Bridge Calculator
Calculate the unknown resistance in a Wheatstone bridge circuit.
Zener Diode Calculator
Calculate Zener diode current, voltage regulation, and resistor values.
Transformer Ratio Calculator
Calculate transformer turns ratio, primary/secondary voltage and current.
Power Factor Calculator
Calculate power factor, apparent power, real power, and reactive power.
Three-Phase Power Calculator
Calculate three-phase AC power, line current, and phase voltage.
Voltage Drop Calculator
Calculate voltage drop in a wire based on length, current, and conductor size.
Wire Gauge (AWG) Calculator
Find the correct wire gauge (AWG) for your current load and distance.
Home Wiring Load Calculator
Calculate total electrical load of home appliances and circuit capacity.
Electrical Cable Size Calculator
Determine the correct cable cross-section for safe current carrying capacity.
Fuse Size Calculator
Calculate the correct fuse rating for a circuit based on load and safety factor.
Motor Power Calculator
Calculate motor power output, efficiency, and current draw.
Short Circuit Current Calculator
Calculate short-circuit current (Isc) in a single or three-phase system.
AC/DC Efficiency Calculator
Calculate AC to DC conversion efficiency and power loss in rectifier circuits.
Solar Panel Output Calculator
Estimate daily and monthly energy output from a solar panel system.
Solar ROI Calculator
Calculate payback period and return on investment for a solar panel installation.
PV System Size Calculator
Determine the required PV system size to meet your energy consumption.
EV Charging Cost Calculator
Calculate the cost to charge an electric vehicle at home or public stations.
dBm to Watts Calculator
Convert power levels between dBm, watts, and milliwatts.
Decibel Calculator
Calculate decibel levels, power ratios, and voltage ratios for audio and RF.
Introduction
Electricity Converters help you change one electrical unit into another, without guessing or doing manual math. This tool is useful for students, electricians, engineers, and anyone working with electrical circuits. You can convert common values like volts, amps, ohms, coulombs, and more.
How to Use
- 1Choose the type of conversion you need (current, voltage, etc.).
- 2Enter the value you already know (example: 120).
- 3Select the 'From' unit and the 'To' unit.
- 4View the converted result and copy it if needed.
What This Calculator Measures
Formula & Logic
Most conversions use simple scaling factors. For example, moving from base units like Volts to Millivolts involves multiplying by 1000.
Examples
- 120 V 120,000 mV
- 2.5 A 2500 mA
- 5000 C 1.39 Ah
Common Mistakes
- Mixing up current (A) and charge (C)
- Forgetting that milli = 1/1000
- Using the wrong reference for conductance
- Confusing mA with µA
- Rounding too early
Engineering Note
When working with sensitive circuits, parasitic capacitance and inductance can affect performance at high frequencies — even when the calculated values look correct. Always verify converted values against your component datasheets and test under real operating conditions before finalising a design.
Real-World Applications by Category
Electric Charge
Coulombs, Amp-hours, Milliamp-hours
Battery capacity ratings for phones and EVs, capacitor sizing, electroplating calculations.
Electric Current
Amperes, Milliamperes, Microamperes
Circuit breaker sizing, fuse selection, LED driver current settings, Arduino/Raspberry Pi pin limits.
Electric Potential (Voltage)
Volts, Millivolts, Kilovolts
Comparing mains voltages across countries (120 V vs 230 V), sensor output signals, transformer design.
Electric Resistance
Ohms, Kilohms, Megaohms
Resistor selection in PCB design, cable impedance matching, insulation testing.
Capacitance
Farads, Microfarads, Picofarads
Filter design, timing circuits (RC networks), power factor correction, decoupling capacitors.
Inductance
Henries, Millihenries, Microhenries
Inductor selection for DC-DC converters, EMI filter design, inductive load calculations.
Electric Conductance
Siemens, Millisiemens
Determining how easily current flows in a conductor; the inverse of resistance used in admittance calculations.
Electric Field Strength
Volts per metre, Kilovolts per metre
Antenna design, dielectric breakdown thresholds, EMC (electromagnetic compatibility) testing.
Linear & Surface Charge Density
Coulombs per metre, C/m²
Electrostatics problems, capacitor plate modelling, semiconductor doping analysis.
Essential Electrical Formulas
Unit conversions are only part of the picture. These fundamental relationships connect the electrical quantities above and are essential in everyday circuit work:
Ohm's Law
Voltage equals current multiplied by resistance. The foundation of all DC circuit analysis.
Electric Power
Power (watts) equals voltage times current. Used to size wires, fuses, and power supplies.
Capacitor Charge
Charge stored (coulombs) equals capacitance (farads) times voltage. Key for timing and filtering circuits.
Inductor Voltage
Voltage across an inductor equals inductance times the rate of current change. Critical for switching converters.
SI unit definitions per NIST SP 330; formulas are standard electrical engineering relationships.