House Calculator for my project

Hello guys,

I am having problems with solving an issue which is finding a suitable equation for gas and water consumption, tried to find a suitable equation for my calculator project but no luck....i want to use something similar to this:-

Power = 2400watt/1000 x 4hours x 13.94cents = $1.34
Gas = ?
Water = ?
but for gas and water, if anyone got answers to this kind of problem please reply back would be appreciated. Thank you.

Consider volume - say cubic metres.

Pull out the utility bills, I'm sure the method they use will be a good start

mm the Utility Bills actually came out to be quite useful..many thanks for that Fordy....i might have questions later on but at the moment its all fixed :)