Power supply? help :( im a noob

im trying to find out my power supply wattage but im not sure how im looking at the sticker on the power brick and i just see loads of confusing numbers and letters can someone help me out? 

On the sticker

Model number ga240pe1-00

Input 100-240v-3.5  50-60hz

Output 19.5   12.3

If you need more info just message back thanks :)