# Watts to Amps Calculator & Conversion – DC/AC (1 & 3 Phase)

## How to Convert Watts (W) to Amperes (A) – Simple and Advanced Calculators

The following two (basic and advanced) calculators can be used to calculate and convert the electric current in amperes from electric power in watts and voltage in volts.

In Advanced Watts to Amps Calculator, We can calculate the electric current in amperes, milliamperes or kiloamperes from electric power in in watts, milliwatts or kilowatts and RMS voltage in volts for DC circuits, AC, 1-Phase and 3-Phase circuits having the Line to Line voltage (Delta Connection), Line to Neutral voltage (Star Connection) and Power Factor (P.F). You may read more about the difference between Star (Y )and Delta (Δ) Connections.

In Simple Watts to Amps calculator, any two known values among three (P, I and V) can be used to calculate power in watts, current in amperes or voltage in volts.

Note 1: If you are on mobile phones device, click on the three dots “” beside the “Advanced Calculator” to select the simple calculator. For better experience through mobile phones, use the calculator in landscape position.

### Watts to Amps Calculator

 Select Current Type DCAC – Single PhaseAC – Three Phase Enter Power in Watts mWWkW Select Voltage Type Line to line voltageLine to neutral voltage Enter Voltage in Volts mVVkV Enter Power Factor Current Value in Amps A Current Value in KiloAmp kA Current Value in MillAmps mA
Simple Watts to Amps Calculator

 Power (P) Watts Voltage (V): Volt Current (I) AmpsMilliamps

Note 2: For higher values like, 5×103, 10×10-6, 1.6 x1012, enter the value like this for scientific notation as 5e3, 10e-6, 1.6e12 etc.

I = P ÷ V

### AC Single Phase Power in Watts to Amps Conversion

I = P ÷ (V  x Cosθ)

### AC Three Phase Power in Watts to Amps Conversion

#### Conversion with Line to Line Voltage (VL-L)

I = P ÷ (√3 x VL-L x Cosθ)

#### Conversion with Line to Neutral Voltage (VL-N)

I = P ÷ (3 x VL-N x Cosθ)

Where:

• P = Power in watts
• V = Voltage in volts
• I = Current in amperes
• Cosθ = Power factor in AC circuits
• VL-L = Line to Line Voltage in 3-Phase Circuits
• VL-N = Line to Neutral Voltage in 3-Phase Circuits

### Typical Power Factor Values for Equipment and Appliances

For accurate calculation, use the exact value of power factor instead of the typical value by calculation or check the nameplate data rating of the appliance.

 Electrical Equipment and Appliances P.F = Cosθ Motor & Transformer Induction Motor at No Load 0.35 Induction Motor at Full Load 0.85 Transformer at No Load 0.15 Lamps Incandescent Lamps 1.0 Fluorescent Lamps (Uncompensated) 0.5 Fluorescent Lamps (Compensated) 0.9 Discharge Lamps 0.4 to 0.6 Mercury Vapor Lamp 0.5 Sodium Vapor Lamp 0.6-0.7 Ovens Ovens using Resistance Elements 1.0 Induction Heating Ovens (Compensated) 0.85 Dielectric Type Heating Ovens 0.85 Welding Resistance Type Soldering Machines 0.8 to 0.9 Fixed 1-phase Arc Welding Set 0.5 Arc Welding Motor Generating Set 0.7 to 0.9 Arc Furnace 0.8 to 0.9 Arc Welding Transformer Rectifier Set 0.7-0.8 AC-DC Drives & Converters AC-DC Converters 0.95 AC Drive 0.4-0.7 DC Drive 0.6-0.9 Pure Resistive Load 1 Pure Inductive & Capacitive Load 0

### How to Convert Watts to Amps?

The basic Amps to Watts calculator uses the Watt’s Law which states that “The total power of an electric circuit is equal to the product of electric current and voltage in that circuit”. i.e.

Current (I) in Amps = Power (P) in Watts ÷ Voltage (V) in Volts

I = P ÷ V

If we put the values of V and I in the above equations from Ohm’s law, we get the current as follow as well.

I = √(P ÷ R)

I = V ÷ R

Examples:

Current = Power ÷ Voltage

• I = 600W ÷ 120V = 5 A
• I = 2070W ÷ 5V = 9 W
• I = 48W ÷ 12V = 4 A

### Equivalent Watts and Amps at 120V AC, 230V AC and 12V DC

The following table shows the different values of amperes and wattage for 120V and 230V AC and 12V DC at unity power factor “1”.

 Current in Amp Power in Watts Voltage in Volts 1 120 W 120V AC 230 W 230V AC 12 W 12V DC 5 600 W 120V AC 1150 W 230V AC 60 W 12V DC 10 1200 W 120V AC 2300 W 230V AC 120 W 12V DC 15 1800 W 120V AC 3450 W 230V AC 180 W 12V DC 20 2400 W 120V AC 4600 W 230V AC 240 W 12V DC 30 3600 W 120V AC 6900 W 230V AC 360 W 12V DC 50 6000 W 120V AC 11500 W 230V AC 600 W 12V DC 70 8400 W 120V AC 16100 W 230V AC 840 W 12V DC 100 12000 W 120V AC 23000 W 230V AC 1200 W 12V DC

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