Watts to Amps Calculator
Convert watts to amps (or amps to watts) at any voltage. Designed for 12V, 24V, 48V DC camper and off-grid loads, plus 120V and 230V AC with optional power factor.
Watts to Amps Calculator
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Result
For DC and resistive AC: P = V × I. For AC with motors or inverters, P = V × I × power factor.
Need a complete wiring diagram?
VoltPlan designs full electrical systems for campers, boats, and off-grid setups with automatic wire sizing, fuse placement, and solar configurations.
Design Your SystemWatts to Amps Reference Chart
Common DC load wattages converted to amps at the typical camper, RV, boat, and off-grid system voltages. Use this for quick wire-and-fuse sizing without re-running the math.
| Watts | @ 12V | @ 24V | @ 48V | @ 120V | @ 230V |
|---|---|---|---|---|---|
| 5W | 0.42 A | 0.21 A | 0.10 A | 0.04 A | 0.02 A |
| 10W | 0.83 A | 0.42 A | 0.21 A | 0.08 A | 0.04 A |
| 25W | 2.08 A | 1.04 A | 0.52 A | 0.21 A | 0.11 A |
| 50W | 4.17 A | 2.08 A | 1.04 A | 0.42 A | 0.22 A |
| 100W | 8.33 A | 4.17 A | 2.08 A | 0.83 A | 0.43 A |
| 200W | 16.67 A | 8.33 A | 4.17 A | 1.67 A | 0.87 A |
| 500W | 41.67 A | 20.83 A | 10.42 A | 4.17 A | 2.17 A |
| 1000W | 83.33 A | 41.67 A | 20.83 A | 8.33 A | 4.35 A |
| 1500W | 125.00 A | 62.50 A | 31.25 A | 12.50 A | 6.52 A |
| 2000W | 166.67 A | 83.33 A | 41.67 A | 16.67 A | 8.70 A |
| 3000W | 250.00 A | 125.00 A | 62.50 A | 25.00 A | 13.04 A |
Frequently Asked Questions
How do I convert watts to amps?
Divide watts by volts: A = W ÷ V. For 60W at 12V that is 5A. The calculator handles AC power factor automatically when you set it below 1.0 for motor or inverter loads.
How do I convert amps to watts?
Multiply amps by volts: W = V × A. For 5A at 12V that is 60W. For AC with a non-unity power factor: W = V × A × pf.
What is power factor?
The ratio between real power (W) and apparent power (VA). DC and resistive AC loads have pf = 1.0. Motors, transformers, and switching supplies have pf 0.7–0.95.
How many amps does a 1000W inverter draw at 12V?
About 83A continuous (1000 ÷ 12). Real-world: 90–100A including inverter efficiency losses. The wire and fuse must handle the full inverter rating.
Why is the 12V current so much higher than the 230V current for the same load?
Power = V × I, so at lower voltage the current must be higher to deliver the same power. 12V systems need much heavier cabling than 120V or 230V household wiring for the same wattage.
Is power factor relevant for DC?
No. DC has no power factor; W = V × A always. Power factor only applies to AC where current and voltage waveforms can drift out of phase.
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