Energy Cost Calculators

Electricity bills arrive as one number, which makes it almost impossible to tell which appliance is responsible. The electricity cost calculator takes a device's wattage and hours of use and converts it to cost per day, month and year at your own rate — often revealing that the thing running quietly all day costs more than the thing that draws a lot for ten minutes.

The battery runtime calculator answers the other half: given a battery's capacity and depth of discharge, how long it will actually hold up a load during an outage.