Type the brand and model into Google. The wattage is almost always part of the model name. 3. Consult Your Pre-built Specs
The only 100% accurate way to know your wattage is to look at the physical sticker on the power supply unit. how to tell power supply wattage
If you are checking your wattage because you want to upgrade your graphics card, use an online . Input your parts: List your CPU, GPU, and number of drives. Type the brand and model into Google