Watts to Amps Calculator
Instantly convert electrical power to current. Accurate and easy to use for all electrical systems.
How to Convert Watts to Amps
Converting Watts (Power) to Amps (Current) is a fundamental calculation in electrical engineering and DIY projects. Whether you are sizing a circuit breaker for your home renovation or calculating the battery drain for your RV, understanding this relationship is crucial for safety and efficiency.
What are Watts?
Watts (W) measure the rate of power consumption. Think of it as the "horsepower" of an electrical device. A higher wattage means the device consumes more energy per second to do its work.
What are Amps?
Amps (A) measure the flow rate of electric charge. Think of it as the volume of water flowing through a pipe. You need thicker wires (pipes) to handle higher amperage (water flow) safely.
DC DC Formula
For batteries, solar panels, and automotive circuits.
I = P ÷ V
Current (Amps) = Power (Watts) ÷ Voltage (Volts)
AC AC Single Phase
For household appliances and standard outlets.
I = P ÷ (V × PF)
PF = Power Factor (typically 0.8 to 0.9)
3Φ AC Three Phase
For industrial motors and heavy machinery.
Line-to-Line (Most Common)
I=P÷(√3×V×PF)
Line-to-Neutral
I=P÷(3×V×PF)
Typical Power Factor (PF) Values
The Power Factor depends on the type of device. Use these estimation values if unsure:
Quick Wire Size Guide
Once you calculate the Amps, you need to choose the right wire size (AWG) to prevent overheating.
*General guide for copper wire at standard temperatures. Check local codes.
Common Wattage to Amps Conversion Chart
The following table shows the current draw for common power ratings across different standard voltages. Note how the current drastically increases as the voltage drops—this is why 12V systems need much thicker wires!
| Power (Watts) | 12V (DC) | 24V (DC) | 120V (AC) | 220V (AC) |
|---|---|---|---|---|
| 50 W | 4.17 A | 2.08 A | 0.42 A | 0.23 A |
| 100 W | 8.33 A Thicker wire needed | 4.17 A | 0.83 A | 0.45 A |
| 500 W | 41.67 A Dangerous High Current | 20.83 A | 4.17 A | 2.27 A |
| 1000 W | 83.33 A | 41.67 A | 8.33 A | 4.55 A |
| 2000 W | 166.6 A (N/A) | 83.33 A | 16.67 A | 9.09 A |
Real-World Scenarios
Solar Panel Setup
The Scenario
You have a 100W solar panel connected to a 12V battery system. You need to size the charge controller.
The Math
Kitchen Microwave
The Scenario
A standard microwave is rated at 1200 Watts and plugs into a 120V outlet.
The Math
*Safe for a standard 15A or 20A kitchen circuit breaker.
Key Features of Watts To Amps.net
- Accurate Calculations: Our tool uses standard electrical engineering formulas to ensure precise results for every conversion.
- Versatile Support: Whether you're working with DC automotive systems, AC household circuits, or industrial Three-Phase power, we've got you covered.
- User-Friendly Interface: Designed for simplicity and speed, allowing you to get the answers you need without any hassle.
- Educational Resources: We don't just give you the numbers; we provide formulas, guides, and practical examples to help you understand the underlying concepts.
- Mobile Optimized: Access our calculator from anywhere, on any device—perfect for quick checks on the job site.
Important Considerations
Safety Warning: Electrical work can be dangerous. The information provided here is for educational and estimation purposes only.
- Consult a Professional: Always consult with a certified electrician for actual wiring, installation, and safety compliance.
- Wire Sizing: Calculating Amps is just the first step. You must ensure you use the correct wire gauge (AWG) to handle the current without overheating.
- Circuit Breakers: Verify that your circuit breaker or fuse is rated appropriately for the load to prevent tripping or fire hazards.
- Voltage Drop: For long cable runs, especially in low-voltage DC systems, consider voltage drop which can significantly affect performance.
- Device Ratings: Always check the manufacturer's specifications for your specific devices, as actual power consumption may vary.