Firstly, I'm not really an electrician or an electrical guy with lots of knowledge about electronics but I'm always interested learning to it.

Yesterday, I asked my wife to help me out determining the wattage (electrical power) of an electrical device such as TV, Reff, PC, Laptop, Tablet, etc, etc anything around the house that uses electricity and I plotted each one of them and log at least 3 wattage and average it.

I have this:

![enter image description here](https://i.stack.imgur.com/GG34u.png)

that's 95% of our electrical devices here around the house. I can play with values and see how much it costs if this device is turned on for this hours. But doing it is pretty tough job because we had to turn off everything and turn on and off each device to check its wattage.

But I wonder if an multimeter can do this? Can I check the wattage of an electrical device such as TV, Laptop , etc even if they are plugged in?

I only have this cheap small digital multimeter I carry around the house.
![enter image description here](https://i.stack.imgur.com/X0fZm.png)

Here in Philippines, meters are exposed and some are digital, like ours. That's the way I check the wattage of the device - sort of like this one:

![enter image description here](https://i.stack.imgur.com/3n29F.jpg)