This is the comment I came here for. I bought a Kill A Watt some years ago when I wanted to get a feel for what my devices were using and can't say enough good

This is the comment I came here for. I bought a Kill A Watt some years ago when I wanted to get a feel for what my devices were using and can't say enough good things about it. For USB, I also recommend a USB Power Meter: https://www.amazon.com/gp/product/B01J7236K2 https://www.amazon.com/gp/product/B01J7236K2 to see how much current your peripherals use when charging/when full.