To calculate your consumption, Hydro-Québec uses an electricity meter that measures the kilowatthours you have used in a given period.

The kilowatthour (kWh) is a time-based unit of electricity consumption.

• watt = basic unit of power of an electrical appliance
• 1 watthour = 1 watt of power used over a 1-hour period
• 1 kilowatthour = 1,000 watthours

In your opinion, what consumes more electricity: a 1,000-watt (1 kW) baseboard heater operating for one hour, or a 100-watt (0.1 kW) light bulb left on for 10 hours? And how much does that amount to in dollars?

Baseboard heater
	Wattage (W)	1,000
	1,000
=	Wattage (kW)	1
x	Usage (hours)	1
=	Consumption (kWh)	1
x	Cost per kWh ($)	0.0733
=	Cost of the electricity consumed ($)	0.0733

Bulb
	Wattage (W)	100
	1 000
=	Wattage (W)	0.1
x	Usage (hours)	10
=	Consumption (kWh)	1
x	Cost per kWh ($)	0.0733
=	Cost of the electricity consumed ($)	0.0733

Surprised? The same amount of electricity is consumed in both cases.

• Use this tool to calculate the consumption of your appliances. The only thing you need to know is their wattage (in W or kW).
• To determine the wattage of your appliances, consult the chart showing the average annual consumption of common appliances.
• To compare the cost of electricity in different cities, consult the comparative index of electricity prices.