maybe I got the metric wrong. A few weeks ago, I lived in a house which had a smart meter monitor, so I could watch from inside how much energy I’m using. Its for fridge/computer and light. Pretty sure what I saw was .300-500 KwH. Occasionaly when I turn on microwave, it will jump to 1kwH
Your units are wrong?
Half a kilowatt-hour would be possible with only a very efficient refrigerator (like a Sundanzer), moderate lighting (e.g., LED lighting) and laptop or other computer with low power consumption.
You are confusing energy and power. Power is the rate of energy consumption. Energy is power integrated over time. If you know how much power you were using at each instant during the day, then you can calculate how much energy you used that day.
One kilowatt hour is 1000 watts used for one hour. If your microwave uses 1000 watts, then, if you run it all day, it will contribute 24 kwh to your electric bill. On the other hand, if you use it five minutes, then it will account for only 0.083 kwh (1000 watts for 5/60ths of an hour).
Your meter reports it as KiloWatts (not kwH).
So you use 0.300-0.500 KW, which is about right for a home where the big stuff is off (stove, dryer, etc.)
So if you are drawing 0.500 KW for 24hrs you multiply the two and get 12kw-H for the day.