📖 Ohm's Law Advanced Calculator
Ohm's Law is the fundamental relationship between voltage, current, and resistance in electrical circuits: V = I × R. This advanced calculator allows you to enter any two values and instantly get the other two, including power (P = V × I). Perfect for circuit design, troubleshooting, and electronics education.
📐 Ohm's Law Formulas
Voltage: V = I × R | V = P / I | V = √(P × R)
Current: I = V / R | I = P / V | I = √(P / R)
Resistance: R = V / I | R = V² / P | R = P / I²
Power: P = V × I | P = I² × R | P = V² / R
📊 Ohm's Law Triangle
| Formula | When to Use |
|---|
| V = I × R | Find voltage when current and resistance are known |
| I = V / R | Find current when voltage and resistance are known |
| R = V / I | Find resistance when voltage and current are known |
| P = V × I | Find power when voltage and current are known |
| P = I² × R | Find power when current and resistance are known |
| P = V² / R | Find power when voltage and resistance are known |
📌 Common Electrical Values
| Device / Application | Voltage (V) | Current (A) | Resistance (Ω) | Power (W) |
|---|
| LED (Red) | 2.0 | 0.02 | 150 | 0.04 |
| LED (White) | 3.2 | 0.02 | 90 | 0.064 |
| 100W Bulb (230V) | 230 | 0.43 | 529 | 100 |
| 60W Bulb (230V) | 230 | 0.26 | 882 | 60 |
| Small Motor | 12 | 2.0 | 6 | 24 |
| USB Charger | 5 | 2.0 | 2.5 | 10 |
| Car Battery | 12 | 100 | 0.12 | 1200 |
💡 How to Use This Calculator
- Enter any TWO values: Voltage (V), Current (A), Resistance (Ω), or Power (W)
- The calculator automatically computes the other two values
- Use preset buttons for quick examples
- Click "Clear All" to reset all inputs
- Results show all four values with appropriate units
❓ Frequently Asked Questions (FAQ)
❓ What is Ohm's Law? ▼
Ohm's Law states that the current through a conductor is directly proportional to the voltage across it, and inversely proportional to the resistance. Formula: V = I × R.
❓ How do I calculate power using Ohm's Law? ▼
Power can be calculated using P = V × I, P = I² × R, or P = V² / R. This calculator provides all three methods based on available inputs.
❓ What is the difference between AC and DC Ohm's Law? ▼
For DC and resistive AC loads, Ohm's Law works the same. For inductive/capacitive AC circuits, impedance (Z) replaces resistance (R).
❓ What is the unit of resistance? ▼
Resistance is measured in Ohms (Ω), named after German physicist Georg Simon Ohm.
❓ Why can't I enter all four values? ▼
You only need to enter any two values. The calculator finds the other two automatically. Entering all four would create conflicting results.
❓ What is the power triangle? ▼
The power triangle shows the relationship between P (power), V (voltage), and I (current). P = V × I is the basic power formula.