Volts to Amps Calculator
Determining current draw when plugging a device into variable voltage supplies. Calculates resulting current flow based on supply voltage and load resistance or wattage.
Step-by-Step Derivation ▼ Show Steps
Calculations adhere to standard electrical equations and National Electrical Code guidelines.
Engineering Principles & Calculations
This calculator uses the exact mathematical relationships between Voltage (V), Resistance (Ω) or Power (W) to determine Current (Amperes). In practical applications, electrical systems must account for safety derating factors, nominal vs actual voltages, and conductor resistance losses.
Calculates resulting current flow based on supply voltage and load resistance or wattage.
Typical Application & Best Practices
Determining current draw when plugging a device into variable voltage supplies.
Volts to Amps Calculator Benchmark Lookup Table
| Wattage | Voltage | Current (Amps) | Min Breaker | Recommended Wire |
|---|---|---|---|---|
| 500 W | 120V AC | 4.17 A | 15 A | 14 AWG |
| 1000 W | 120V AC | 8.33 A | 15 A | 14 AWG |
| 1500 W | 120V AC | 12.50 A | 20 A | 12 AWG |
| 1800 W | 120V AC | 15.00 A | 20 A | 12 AWG |
| 2400 W | 240V AC | 10.00 A | 15 A | 14 AWG |
| 4500 W | 240V AC | 18.75 A | 30 A | 10 AWG |