Volts to Watts Calculator

The volts to watts calculator supports calculations for direct current (DC) and alternating current (AC) circuits, both single-phase and three-phase. Simply select the circuit type, enter the voltage (V) and current (A) values (for AC circuits, some options also require the power factor PF), click “Calculate Power”, and you'll get the desired power value (W) in a flash. Whether you're troubleshooting a circuit or planning a sustainable energy system, this calculator will help you!

Volts to Watts Calculator



Power: 0 W

Volts to Watts formula

The Volts to Watts calculator is primarily used to convert voltage (Volts, V) and current (Amperes, A) to power (Watts, W). This process is based on the basic definitions and formulas for calculating electrical power. Below are the formulas and related instructions for the Volts to Watts calculator:

DC volts to watts calculation formula

The powerPin watts (W) is equal to the voltageVin volts (V), times the currentIin amps (A):

P(W)=V(V)×I(A)

Alternating current circuit (AC)

In AC circuits, since the voltage and current may not be exactly in phase, the power factor (PF) needs to be taken into account to calculate the actual active power.

Single-phase AC circuits

For a single-phase AC circuit, the formula for power (P) is:

P(W)=PF×I(A)×V(V)
  • PF: Power factor, a number between 0 and 1, indicates the phase relationship between voltage and current. For purely resistive circuits, PF = 1; for inductive or capacitive circuits, PF may be less than 1.

Three-Phase AC Circuits

For three-phase AC circuits, the calculation of power is slightly more complicated because it involves the relationship between three-phase voltages and currents.

  • Line-to-line voltage (VL-L): the voltage between any two phases in a three-phase circuit.
  • Line-to-neutral voltage (VL-N): the voltage between a phase and neutral in a three-phase circuit.

Calculation with line to line voltage

The power Pin watts (W) is equal to square root of 3 times the power factor PF times the phase current I in amps (A), times the line to line RMS voltage VL-L in volts (V):

P(W)=3×PF×I(A)×VLL(V)

Calculation with line to neutral voltage

The power P in watts (W) is equal to 3 times the power factor PF times the phase current I in amps (A), times the line to neutral RMS voltage VL-N in volts (V):

P(W)=3×PF×I(A)×VLN(V)

The heart of the Volts to Watts calculator lies in the use of voltage, current and power factor (for AC circuits) to calculate power. Whether it is a DC circuit or an AC circuit, the conversion is easy once the appropriate formulas have been mastered. In practice, these formulas are important for circuit design, equipment selection, and power analysis.

Applications in solar power systems

The Volts to Watts calculator plays an important role in solar power systems by calculating the amount of power generated by solar photovoltaic panels, i.e., converting voltages (Volts) and currents (Amperes) to watts. This conversion is essential for evaluating the performance of a solar power system, designing an appropriate system configuration, and performing an energy efficiency analysis. The following is a description of the application of the Volts to Watts calculator to solar power systems:

PV Panel Performance Evaluation

  • Real-Time Power Calculator: By measuring the output voltage and current of a PV panel under specific lighting conditions, the Volts to Watts calculator can instantly calculate the output power under those conditions. This helps to understand the panel's ability to generate power and assess whether it meets design requirements.
  • Maximum Power Point Tracking (MPPT): In solar power systems, it is often necessary to find the maximum power point (MPP) of the PV panels to ensure that the system operates at maximum efficiency.The Volts to Watts calculator can assist in the implementation of the MPPT algorithm, which allows the panels to operate close to the MPP point, either by adjusting the load resistor or by using a specialized MPPT controller.

System Design and Optimization

  • System Configuration Design: When designing a solar power system, it is necessary to determine the number and type of panels, as well as the capacity of the inverter, based on the power demand and available PV resources, etc. The Volts to Watts Calculator helps engineers to calculate the required power based on the expected voltage and current ranges, so as to select the appropriate components.
  • Energy Efficiency Optimization: By calculating the output power of the panels under different lighting conditions, the overall energy efficiency of the system can be evaluated. Based on this data, the system can be optimized, such as adjusting the mounting angle of the panels, adding mirrors, or adopting a more efficient inverter, in order to improve the system's power generation efficiency and reliability.