Many people don’t really pay attention to their monthly hydro bill.  Your hydro bill is comprised of electricity consumption, delivery charges for the service, regulatory charges and taxes.  Having a better understanding of how your electricity consumption is calculated might save you some dollars every month.

The first thing to know is that electricity usage is calculated in kilowatt-hours.  A kilowatt-hour is 1000 watts used for one hour.  For example, a 100 watt light bulb operating for 10 hours would use one kilowatt-hour.  The number of kilowatt-hours (kWh) multiplied by the kWh rate equals cost of usage.

In Ontario, the kWh rate is set by the Ontario Energy Board and it’s based on time-of-usage (TOU).  The rate is split into three groups: 1) Off-peak hours, 2) Mid-Peak hours, and 3) On-peak hours.  The peak hours vary between summer months (May 1 to October 31) and winter months (November 1 to April 30).

The most current kWh rates as of November 1, 2019 are as follows:


TOU price periods


 November 1, 2019 rates

Off-Peak (Weekdays 7 p.m. – 7 a.m.,

all day weekends and holidays)



10.1 ¢/kWh


Mid-Peak (Weekdays 11 a.m. – 5 p.m.)



14.4 ¢/kWh



(Weekdays 7 a.m. – 11 a.m. and 5 p.m. – 7 p.m.)



20.8 ¢/kWh

How do I calculate how much electricity an appliance uses?

You can calculate the cost of any device that uses power by following these five simple steps:

  1. Find the wattage on the appliance label. Most high-power appliances have an energy label on the back or base of the appliance.
  2. Multiply wattage by hours used each day.
  3. Divide the result by 1,000.
  4. Multiply your answer by the number of days you’re measuring.
  5. Multiply by the cost of electricity per kWh.

For instance, you plug in your truck for six hours overnight (during off-peak hours).  Most block heaters consume on average between 750 Watts and 1000 Watts.  For this example, we will use 750 Watts.

750 Watts x 6 hours = 4,500 Watts

4,500 Watts / 1,000 = 4.5 kWh

4.5 kWh x 30 days = 135 kWh

135 kWh x 0.101 (10.1 ¢/kWh*) = $13.64

Your truck costs $13.64 per month to plug in overnight for six hours.

*Note that the rate used here is the off-peak rate noted above as prescribed by the Ontario Energy Board.

If you are looking to save money on your hydro bill, it makes sense to do most of your electricity-consuming tasks during weekends and weekday off-peak hours.  Here are a few tips to help you save on your monthly energy bills:

Wash clothes over the weekend or during off-peak hours

Wash your clothes in cold water

Hang your laundry to dry

Turn off unnecessary lights

Upgrade your light bulbs

Use natural light

Unplug unused electronics

Use a fan instead of the air conditioner


Use a programmable thermostat

Install energy efficient windows

Cover your windows

Caulk and weather strip your windows and doors

Skip the heat dry setting in the dishwasher

Upgrade your appliances to Energy Star

Use smart power strips

Use the microwave or toaster oven to heat up small things

Ontario Electricity Rebate

Effective November 1, 2019, the Ontario government has added an expanded rebate that will provide bill relief on customer bills. For more information, visit the Ontario government website.