Amps to watts Calculator Online – Instantly convert Amps to Watts and Watts to Amps with our free online calculator. Supports DC, AC Single Phase, and AC Three Phase calculations.
⚡ Power Calculator
Understanding the Basics: Amps, Watts, and Volts
Before using the calculator, it is helpful to understand the relationship between these three fundamental electrical terms. A common analogy is to think of electricity like water flowing through a pipe:
- Amps (Amperes): Think of this as the volume of water flowing through the pipe. It measures the flow rate of electricity and is represented by the symbol I (Current).
- Volts (Voltage): Think of this as the water pressure. It measures the force pushing the electricity through the circuit and is represented by the symbol V.
- Watts (Power): This measures the total work the water can do (like spinning a water wheel). It represents the power used or produced and is represented by the symbol P or W.
The “Watt’s Law” Formula
The relationship between these three variables is defined by Watt’s Law:
Power (P) = Current (I) × Voltage (V)
How to Convert Amps to Watts
The calculation changes slightly depending on the type of current you are using: Direct Current (DC) or Alternating Current (AC).
1. DC (Direct Current) Calculation
This is used for batteries, solar panels, and automotive circuits. The formula is linear and does not require a power factor.
Formula: Watts = Amps × Volts
You have a 12V car battery and a stereo drawing 5 Amps.
Calculation: 5A × 12V = 60 Watts
2. AC (Alternating Current) Single Phase
This is the standard electricity found in household wall outlets. For AC, we must account for the Power Factor (PF). The Power Factor represents efficiency (usually between 0.8 and 1.0 for home electronics).
Formula: Watts = Amps × Volts × Power Factor
A washing machine draws 10 Amps from a 120V outlet with a Power Factor of 0.9.
Calculation: 10A × 120V × 0.9 = 1,080 Watts
3. AC Three Phase (Line-to-Line)
Three-phase power is typically used in industrial settings for heavy machinery. The formula includes the square root of 3 (approx. 1.732).
Formula: Watts = Amps × Volts × Power Factor × √3
How to Convert Watts to Amps
To calculate the electrical current (Amps) when you know the Power (Watts) and Voltage, you rearrange the formulas above.
1. DC Formula
Amps = Watts ÷ Volts
Example: A 100W light bulb on a 12V battery draws approx 8.33 Amps.
2. AC Single Phase Formula
Amps = Watts ÷ (Volts × Power Factor)
3. AC Three Phase Formula
Amps = Watts ÷ (Volts × Power Factor × √3)