Formula: Watts = Volts × Amps (W = V × A)
Power Adapter Wattage Calculator
Calculate the total power in Watts (W) produced by any power supply brick or required by your electronic gadget.
Try Common Ratings:
V
A
Total Electrical Power
24 W
Formula: 12 V × 2 A = 24 Watts
Crucial Rule: Wattage Alone Does NOT Guarantee Compatibility
A 24V · 1A adapter and a 12V · 2A adapter are both exactly 24 Watts. However, plugging a 24V adapter into a 12V device will immediately destroy it! Always match Voltage (V), Polarity, and Connector Dimensions first.
Ohm & Watt Law
P = V × I
Power in Watts equals the voltage pressure multiplied by the current volume flowing.
mA Conversion
1,000 mA = 1 A
Small electronics list current in milliamps. Always divide by 1,000 to find full Amperes.
Thermal Headroom
+20% Is Ideal
Using an adapter with 20% more wattage than your device draws ensures it runs cool and lasts longer.
Want to check full adapter compatibility?
Verify voltage match, current capacity, DC barrel dimensions, and polarity with our instant evaluation engine.
Open Master Compatibility Checker