The most accessible method for measuring watts is by using a dedicated plug-in power meter, often referred to as a “Kill-a-Watt. ” This device acts as a pass-through meter, plugging directly into a standard wall outlet, with the appliance then plugging into the meter itself. Knowing a device's wattage can help you estimate your electricity bill, select appropriate power supplies, or even design off-grid solar systems. This is where the versatile multimeter comes into play. Measurement At the case of actual DC driven equipment, input level of both DC voltage and DC current is not stable. Escape will cancel and close the window. Consistent procedures ensure accuracy.