How do I read *instant* wattage draw from my spinning-disc electric meter?
Yes.  You can determine your instant watts or kilowatts by using a stopwatch to time how long the disc takes to go around.  Then you need to do a little bit of math.   Not too much, promise :) 

First, look for a figure somewhere on your electric meter called Kh. 7.2 is a common number, so you'd see a marking like 7.2 Kh or perhaps a different number. ** 



Take the Kh number and multiply it by 3600.  You can call this number Ks.  You might as well write this number on the meter, you'll be using it a lot.  *** 

Use a stopwatch/phone to count the number of seconds per 1 revolution of the disc.  (If it's moving too fast or you want more precision, time 10 revolutions and divide by 10.) 

Start with the Ks number (Kh x 3600) and now divide by the number of seconds. That is the number of watts being used right now. **** For instance if Ks is 25920 and it took 6 seconds, 25920/6 is 4320 watts.

If you want kilowatts, divide watts by 1000 (4.320 kw). 



** gory details: Kh is the number of watt-hours per revolution.  A watt-hour is 1 watt for 1 hour. *If you had only a 1-watt LED nightlight burning, it would take Kh hours to turn.* 

*** gory details: multiplying Kh by 3600 gives the number of watt-seconds per revolution, since there are 3600 seconds in an hour.  By the way, for a 7.2Kh meter, this number will be 25920. 

**** gory details: Ks is the watt-seconds per revolution.  Divide by the number of seconds per revolution, the result is watts! 

***** gory details: another example picture.