Wattage to Amperage Calculator
Calculate current, power, and voltage in DC and AC electrical circuits
Electrical Circuit Calculator
Direct Current (DC) - constant voltage and current
Electrical power consumed or supplied
Circuit voltage (RMS for AC)
Calculation Results
Formula used: P = V × I
Circuit: Direct Current (DC) - constant voltage and current
Example Calculations
DC Circuit Example
Given: Power = 1500 W, Voltage = 120 V (DC)
Formula: I = P ÷ V
Calculation: I = 1500 W ÷ 120 V
Result: I = 12.5 A
Analysis: Standard household appliance current
AC Single Phase Example
Given: Power = 2400 W, Voltage = 240 V, PF = 0.8
Formula: I = P ÷ (V × PF)
Calculation: I = 2400 W ÷ (240 V × 0.8)
Result: I = 12.5 A
Analysis: Common for resistive-inductive loads
AC Three Phase Example
Given: Power = 5000 W, Voltage = 400 V (L-L), PF = 0.9
Formula: I = P ÷ (√3 × V × PF)
Calculation: I = 5000 W ÷ (√3 × 400 V × 0.9)
Result: I = 8.01 A per phase
Analysis: Industrial motor application
Common Electrical Values
Power Factor Guide
Unity (1.0)
Resistive loads (heaters, incandescent bulbs)
Good (0.9-0.95)
Well-designed systems, corrected loads
Fair (0.8-0.9)
Typical inductive loads, motors
Poor (<0.8)
Heavily inductive, needs correction
Electrical Formulas
DC Power
P = V × I = I² × R = V²/R
AC Single Phase
P = V × I × PF
S = V × I (Apparent Power)
AC Three Phase
P = √3 × V × I × PF (L-L)
P = 3 × V × I × PF (L-N)
Ohm's Law
V = I × R
I = V/R, R = V/I
Understanding Electrical Calculations
Basic Electrical Principles
Electrical power represents the rate of energy transfer in an electrical circuit. The relationship between power (watts), voltage (volts), and current (amperes) forms the foundation of electrical calculations and is governed by fundamental laws.
DC vs AC Circuits
- •DC: Constant voltage and current, simple P = V × I
- •AC: Alternating voltage/current, requires power factor
- •Three-phase: More efficient for high-power applications
Power Factor Importance
Power factor is crucial in AC circuits as it represents the efficiency of power usage. A low power factor means more current is needed to deliver the same power, resulting in higher energy costs and system losses.
Safety Considerations
Circuit Types and Applications
DC Applications
- • Battery-powered devices and vehicles
- • Solar panels and energy storage systems
- • Electronics and computer systems
- • LED lighting and control systems
AC Applications
- • Household appliances and lighting
- • Industrial motors and machinery
- • Power transmission and distribution
- • HVAC systems and large equipment
Real-World Examples
Household Applications
- • Microwave (1500W): ~12.5A at 120V
- • Electric kettle (1800W): ~15A at 120V
- • Hair dryer (1200W): ~10A at 120V
- • LED bulb (10W): ~0.08A at 120V
Industrial Applications
- • 10 HP motor: ~14A at 480V 3-phase
- • Arc welder: 60-200A at various voltages
- • Industrial heater: 50-500A depending on power
- • Large pump: 25-100A at 480V 3-phase