Power Consumption Cost
Instructions
Enter the Watts for an electrical device and enter your pence per kilowatt-hour (just numbers; no "W", no "p", etc.). Then click "Go".
The form will return a guide for how much the device will cost over a number of time periods.
Notes
This only accepts one cost for a kWh; if you have a cheaper night-time rate then you will need to do the extra maths yourself. Sorry.
Although this wants pence and returns pounds, as long as your currency has 100 "pence" in the "pound", the maths will still be valid...
"Quarter" is calculated as three lots of 30 days, so may not be entirely accurate.