From Amy Faulkner:
Electric Meter Cost Calculator - This tool allows you to determine how much power your entire home or office is using at any given time by measuring the speed of the spinning dial in your electric meter. Results are displayed in watts. This Program also allows you to take multiple readings and compare them to each other. This is useful when you are trying to determine how much power a single device in your home is using, such as your air conditioner. Simply take one reading with the AC turned on, and another reading with the AC turned off. This program will automatically find the difference between the two readings and calculate how much electricity the A/C is using. Electric Meter Cost Calculator - also calculates how much you will be charged by your electric company based on your current power usage. For instance, suppose you wanted to know how much it will cost you to run a pool pump non stop, simply take 2 readings and this program will calculate your daily, weekly, monthly and yearly electric costs to run the pool pump, assuming the pumps stays on 24/7. You can also use this program to see how much it is costing you to keep all your small devices plugged in such as cell phone chargers, cable boxes and anything else that is using power. You might be surprised how much electricity your home is costing you even when you think you've turned everything off.