Enter the current
Type the measured or rated current and select milliamps, amps, or kiloamps.
Electrical & Energy Tool
Amps-to-Watts Calculator
Convert electrical current in amps to real power in watts for DC, single-phase AC, and balanced three-phase AC systems. Add voltage and power factor to receive an instant, formula-backed result.
DC and AC formulas
mA, A, and kA support
Clear watt and kilowatt results
Input values
Calculate electrical power
Choose the electrical system, then enter the current, voltage, and AC power factor shown in the equipment specifications.
DC formulaAmps × volts
Single-phase ACIncludes power factor
Three-phase ACBalanced-load formula
Instant conversionWatts and kilowatts
How it works
Convert amps to watts in four steps
The calculator selects the correct real-power equation for the electrical system you choose.
Add the voltage
Use the operating voltage shown on the equipment, power supply, motor, or data plate.
Select the system
Choose DC, single-phase AC, or balanced three-phase AC and enter power factor for AC.
Read the power
View the result in watts and kilowatts, together with the exact formula substitution.
What is an amps-to-watts calculation?
Amps measure electrical current, while watts measure real electrical power. Converting amps to watts helps estimate how much useful power a circuit or device consumes or delivers at a specified voltage. Current alone is not enough because the same current can represent very different power levels at different voltages.
For example, a 5-amp DC load at 12 volts uses 60 watts, while a 5-amp DC load at 230 volts uses 1,150 watts. AC systems can also require power factor because some of the current supports magnetic or electric fields rather than producing useful real power.
Amps-to-watts formulas
Direct current (DC)
Watts = Amps × VoltsSingle-phase alternating current
Watts = Amps × Volts × Power FactorBalanced three-phase alternating current
Watts = √3 × Amps × Line-to-line Volts × Power FactorWhy power factor changes the wattage
Power factor compares real power in watts with apparent power in volt-amperes. At a power factor of 1.00, voltage and current are fully aligned. A lower power factor produces fewer real watts from the same voltage and current. Use the nameplate or manufacturer value whenever available.
Practical uses
When this calculator is useful
Use the calculation as an initial real-power estimate when checking electrical equipment, batteries, appliances, or machinery.
Solar and battery systems
Estimate DC wattage from measured current for panels, batteries, chargers, and inverters.
Household appliances
Estimate appliance power from current draw at the local operating voltage.
Motors and pumps
Include power factor when estimating real input power for common AC machinery.
IT and power supplies
Review approximate power demand for servers, UPS systems, adapters, and electronics.
Commercial equipment
Estimate single-phase or balanced three-phase power from line current and voltage.
Electrical learning
Understand how current, voltage, phase configuration, power factor, and watts relate.
Frequently asked questions
Amps-to-watts calculator FAQs
Clear answers to common questions about electrical current, power, voltage, and AC power factor.
How do I convert amps to watts?
For DC, multiply amps by volts. For single-phase AC, multiply amps by volts and power factor. For balanced three-phase AC, multiply √3 by amps, line-to-line voltage, and power factor.
How many watts is 10 amps at 230 volts?
For DC or single-phase AC at a power factor of 1.00, 10 amps at 230 volts equals 2,300 watts. At a power factor of 0.90, the estimated real power is 2,070 watts.
Why does the calculator ask for power factor?
Power factor determines how much apparent electrical power becomes real power in an AC circuit. A lower power factor produces fewer real watts for the same amps and volts. DC calculations do not use power factor here.
What voltage should I enter?
Enter the actual operating or rated voltage. For three-phase calculations, enter line-to-line voltage because the calculator uses the standard balanced three-phase formula.
Does this calculate input power or output power?
It calculates electrical real power at the point represented by your entered current, voltage, phase arrangement, and power factor. Mechanical or useful output power may be lower because equipment efficiency is not included.
Can measured current produce an exact wattage?
Only when voltage, waveform, and power factor are also accurate. Clamp-meter current alone cannot determine exact real power for many AC loads. A suitable power analyser provides a more reliable measurement.
Are watts and volt-amperes the same?
They are equal when power factor is 1.00. Volt-amperes measure apparent power, while watts measure real power. For single-phase AC, watts equal volt-amperes multiplied by power factor.
Electrical safety reminder
De-energise equipment before inspection and use a qualified electrician for installation, testing, protection design, or work on live electrical systems.