It all depends on your PSU. for examaple 80% energy Efficiency PSU multiply that by the Watts from the wall = gives you the total watts used by your CPU, GPU, Fans, etc... so the maximum power reading from the "wall" for a 1000W with 80% Efficiency is 1250W. Let me know if that answer your question
If the entire computer is using 100Watts and the PSU (at 100Watts) is 80% efficient this means:
- Wall power is 100Watts
- PSU uses 20Watts
- rest of computer uses 80Watts
Sometimes you'll see it written that a graphics card uses "150Watts"; usually that is what the card uses itself. However, because the PSU also has to use energy to supply that power, you in fact use more than 150Watts.
"Wall Power" is the energy that the entire computer is using and what you will be paying for on your electric bill.