In Philippines my country we have 220 V and 240 V appliances and we also tested 110 V appliances here but the problem is we need to convert the voltage of our appliances to 110 V, so we need to use a device that stepping down the voltage commonly known as voltage regulator. Some says the lower the voltage the cheaper the amount paid in your electric bill and I agree with that opinion. Example I have a power heater plug in the wall socket and have a voltage input of 240 V and I have another with 110 V with 10 A current, which is the cheaper? The formula is multiplying the input voltage to input current which is 240 V X 10 A = 2400 W, while in 110 V X 10 A = 1100 W; then if we convert it to kilowatt hour. They will be like these 2400 W will be 2.4 kWh and 1100 W will be 1.1 kWh then we multiply it to how much does electric company charge an amount in every use of electricity per hour. Example, 10 cents per hour so the formula goes like these (kWh x electric company charge per hour usage of electricity = N), 2.4 kWh X 0.10 cents = Php. 0.24 cents, 1.1 kWh X 0.10 cents = Php. .11 cents. Then multiply it again on how many times you used your appliances and you will get the answer how much you will paid to electric company per using of their electric product per month.