Watts to Amps Calculator

Convert between watts and amps for DC, single-phase AC, and three-phase AC circuits

Electrical Power Calculator

Watts → Amps

Calculate current from power and voltage

Amps → Watts

Calculate power from current and voltage

DC Current

Direct current (batteries, solar panels)

Single-Phase AC

Household appliances, lighting

Three-Phase AC

Industrial motors, heavy equipment

W

Electrical power consumed or generated

V

Circuit voltage

Calculation Results

0.000
Current (A)
Direct Current (DC)
Circuit Type

Formula: Enter values to see calculation

Example Calculations

Example 1: DC Circuit (LED Strip)

Power: 24W, Voltage: 12V DC

Calculation: I = P / V = 24W / 12V = 2A

Result: The LED strip draws 2 amperes of current

Example 2: Single-Phase AC (Home Appliance)

Power: 1800W, Voltage: 120V AC, PF: 0.9

Calculation: I = P / (V × PF) = 1800W / (120V × 0.9) = 16.67A

Result: The appliance draws 16.67 amperes from the outlet

Example 3: Three-Phase AC Motor (Industrial)

Power: 15000W, Voltage: 415V (Line-to-Line), PF: 0.85

Calculation: I = P / (√3 × V × PF) = 15000W / (1.732 × 415V × 0.85) = 24.6A

Result: The motor draws 24.6 amperes per phase

Common Electrical Values

Household outlet (US)120V AC
Household outlet (EU)230V AC
Car battery12V DC
Industrial 3-phase415V AC
USB power5V DC

Power Factor Reference

Resistive loads0.95 - 1.0
LED lights0.9 - 0.95
Fluorescent lights0.5 - 0.95
AC motors0.8 - 0.9
Transformers0.95 - 0.99

Quick Formulas

DC Current
I = P / V
Direct current circuits
Single-Phase AC
I = P / (V × PF)
Household appliances
Three-Phase AC
I = P / (√3 × V × PF)
Line-to-line voltage

Understanding Watts, Amps, and Electrical Power

Basic Electrical Units

  • Watts (W): Unit of electrical power - energy per unit time
  • Amps (A): Unit of electrical current - charge flow rate
  • Volts (V): Unit of electrical potential difference
  • Power Factor: Ratio of real to apparent power in AC circuits

Current Types

DC (Direct Current)

Constant voltage and current direction. Used in batteries, electronics, solar panels.

AC (Alternating Current)

Voltage and current alternate direction. Used in power grids, household electricity.

Practical Applications

Circuit Design

  • • Calculate wire size and breaker ratings
  • • Determine power consumption costs
  • • Size electrical components properly
  • • Plan electrical load distribution

Safety Considerations

  • • Prevent circuit overloading
  • • Select appropriate fuses/breakers
  • • Calculate heat dissipation
  • • Ensure code compliance

Three-Phase Power Systems

Line-to-Line (Delta)

Voltage measured between any two phase conductors. Common in industrial applications where high power and efficiency are required. Formula includes √3 factor.

Line-to-Neutral (Wye/Star)

Voltage measured between any phase conductor and neutral. Common in commercial buildings. Provides both single-phase and three-phase power from same system.