Ohm's Law Current Calculator

Calculate electrical current using Ohm's law formulas

Electrical Current Calculator

Choose the calculation method based on available values

Electrical potential difference

Opposition to current flow

Calculation Results

Current (I)

0.1200 A
Milliamperes:120.00 mA
Microamperes:120000.0 μA
Current type:Low Current

Complete Circuit Analysis

Voltage (V):12.00 V
Resistance (R):100.00 Ω
Power (P):1.44 W
All values calculated using Ohm's Law

Safety Classification

🔒 Dangerous: Can cause pain and muscle control loss

Wire Gauge Recommendation

🔌 22-24 AWG: Thin wire for low current electronics

Formula used: I = V/R

Calculation: I = 12.00 V ÷ 100.00 Ω = 0.1200 A

Current classification: Small devices, logic circuits

Electrical Analysis

Current flow: 0.1200 amperes of charge flow per second
🔥 Power dissipation: 1.44 watts of energy consumed
🔋 Voltage drop: 12.00 volts across the component
🛡️ Resistance: 100.00 Ω opposition to current

Example Calculation

Example: Hair dryer current calculation

Given:

• Power (P) = 1500 W

• Voltage (V) = 120 V

• Find: Current (I)

Solution Steps

Using Ohm's Law: I = P / V

I = 1500 W ÷ 120 V

I = 12.5 A

The hair dryer draws 12.5 amperes of current.

Ohm's Law Formulas

Basic Formula
I = V / R
Current from voltage and resistance
Power Formula
I = P / V
Current from power and voltage
Alternative Formula
I = √(P / R)
Current from power and resistance
Related Formulas
V = I × R
R = V / I
P = V × I

Current Safety Levels

< 1 mASafe
1-10 mANoticeable
10-100 mADangerous
> 100 mALife-threatening

Typical Current Values

LED20 mA
Smartphone1-2 A
Lightbulb (60W)0.5 A
Hair Dryer12.5 A
Electric Heater15-20 A

Electrical Safety Tips

Always turn off power before working on circuits

🔧

Use proper wire gauge for expected current

📏

Include 25% safety margin in calculations

🛡️

Install appropriate circuit protection

Understanding Ohm's Law and Current

What is Electrical Current?

Electrical current is the flow of electric charge through a conductor. It represents the amount of electric charge passing through a cross-section of a conductor per unit time. Current is measured in amperes (A), where 1 ampere equals 1 coulomb of charge per second.

Ohm's Law Fundamentals

  • Basic Law: I = V/R (Current = Voltage ÷ Resistance)
  • Power Relation: I = P/V (Current = Power ÷ Voltage)
  • Alternative: I = √(P/R) (Current = √(Power ÷ Resistance))
  • Units: Amperes (A), Milliamperes (mA), Microamperes (μA)

Practical Applications

Circuit Design:

• Calculate wire gauge requirements

• Size circuit breakers and fuses

• Determine component ratings


Troubleshooting:

• Diagnose electrical problems

• Verify proper operation

• Check for overloads

Safety Considerations

  • Low Current (< 1 mA): Generally safe, used in electronics
  • Moderate Current (1-100 mA): Can be dangerous, causes muscle control loss
  • High Current (> 100 mA): Life-threatening, can cause cardiac arrest
  • Wire Sizing: Use appropriate gauge for current carrying capacity