Amps vs Volts vs Watts Explained
Volts (V), amps (A), and watts (W) are related electrical units. The simplest way to connect them is: Watts = Volts × Amps.
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Formulas: W = V × A · A = W ÷ V · V = W ÷ A
What Do Volts, Amps, and Watts Mean?
- Volts (V) = electrical “pressure” pushing electricity through a circuit.
- Amps (A) = how much electrical current is flowing.
- Watts (W) = power: how fast electrical energy is being used.
Quick Relationship (Most Important)
Watts = Volts × Amps
Common Examples
| Device / Scenario | Volts (V) | Amps (A) | Watts (W) |
|---|---|---|---|
| Phone charger (typical) | 5 | 2 | 10 |
| Laptop charger (example) | 20 | 3.25 | 65 |
| Home outlet load (US example) | 120 | 10 | 1200 |
| Space heater (common) | 120 | 12.5 | 1500 |
Real-World Notes
- If voltage stays the same (like a 120V outlet), higher watts means higher amps.
- Circuit breakers are rated in amps (e.g., 15A, 20A).
- Appliance labels often show watts or amps.
Common Mistakes
A common mistake is thinking higher voltage automatically means more power. Power depends on both voltage and current: W = V × A.
FAQ
How do I convert watts to amps? Use A = W ÷ V.
How do I convert amps to watts? Use W = V × A.
What is more important for a breaker rating? Breakers are rated by amps.