7805 Heating up

Hi, I would like to ask again. Why is my 7805 heating up so hot (good thing I have a big heat sink) when it's load is only eating 1A considering it's input voltage to 7805 is 10.3v? Is it because of the wasted power or is it because the load is taking the max current from 7805?

Please don't start a new thread on the same problem as your previous thread.

sorry. please delete this one, because I find my question different

Easy to see why... 10.3V in 5V out

SO! 10.3V-5V =5.3V drop @ 1 Amp... 1Amp x5.3 V = 5.3 Watts!

hot indeed! lol