How many solar panels does an average Canadian home need?

It depends on your use and location. A home using 9,000 kWh a year needs roughly 17 to 21 panels of 430 W, depending on the city, using our model's yields.

How much roof space does one solar panel need?

A typical 430 W panel is about 2 square metres, or 21 square feet. Installers also leave clearances at edges, ridges and around vents, so plan for more than the panel area alone.

Should I size my system to cover 100% of my electricity use?

Not always. In Ontario, credits beyond your yearly use expire, and in net billing provinces exports earn less than you pay. The best payback is often at or a little below your yearly use.

Do I need more panels in winter?

You size for the whole year, not for winter. Under net metering, summer surplus credits cover darker months, so you don't need a system big enough to cover December on its own.

How many solar panels do I need?

Turn your yearly electricity use into a system size and panel count, with yield by Canadian city, roof space per panel and a Toronto example.

5 min read · Updated 2026-10-30

The number of panels you need comes down to three numbers: how much electricity you use in a year, how much each kW of panels makes where you live, and the wattage of the panels. You can do the maths in a few minutes, then check whether your roof has room.

Step 1: Find your yearly electricity use

Add up the kWh on your last 12 bills, or download a year of usage from your utility's website. Use a full year, because heating and air conditioning make some months far higher than others. Our guide to reading your electricity bill shows where to find the number.

If you plan to add an electric vehicle or a heat pump soon, add an estimate for that too. See solar and electric vehicles and solar and heat pumps.

Step 2: Divide by the yield per kW where you live

Yield is how many kWh each kW of panels produces in a year. It depends mostly on location. These are the figures our model produces for a well-placed roof in each city:

City	kWh per kW per year
Regina	1,304
Winnipeg	1,267
Calgary	1,246
Toronto	1,086
Montréal	1,074
Moncton	1,027
Halifax	1,007
Vancouver	964
St. John's	873

The formula is:

System size (kW) = yearly use (kWh) ÷ yield (kWh per kW)

East- or west-facing roofs and shade lower the yield, so your roof may need a slightly bigger system for the same output.

Step 3: Divide by panel wattage

Panels are rated in watts. Our model uses a 430 W panel, which is typical of current residential panels.

Number of panels = system size (W) ÷ panel wattage (W)

Round to a whole panel. Higher-wattage panels mean fewer panels for the same system size. See solar panel types and efficiency.

Step 4: Check your roof space

A 430 W panel is about 1.9 m by 1.05 m, or roughly 2 square metres (21 square feet). Installers also leave clear space at roof edges, ridges and around vents and chimneys, so the usable area is smaller than the whole roof face. Our guide on whether your roof is suitable covers direction, pitch and shade.

A worked example for Toronto

Say a Toronto home uses 9,000 kWh a year.

System size: 9,000 ÷ 1,086 = about 8.3 kW.
Panels: 8,300 W ÷ 430 W = 19.3, so 19 or 20 panels.
Roof space: 20 panels × 2 m² = about 40 m² of panel area, plus clearances.

For comparison, our Toronto sample home ends up with a 7.3 kW system: 17 panels producing about 7,940 kWh a year. That size came from searching for the best payback, which isn't always the size that covers 100% of your use.

Why the best size isn't always 100% of your use

Under Ontario net metering, credits expire after 12 months. A system larger than your yearly use produces credits you can't use. Sizing at or a little below your use avoids waste. See what happens to net metering credits.
With Ontario's HRSP rebate, the system must be sized for on-site use and can't export for credit. That usually means a smaller system matched to daytime use. See net metering vs the HRSP rebate.
In net billing provinces such as BC, Saskatchewan and Manitoba, exports earn less than you pay for power, so oversizing pays poorly.
Fixed costs such as permits and electrical work are spread over more panels in a bigger system, which can lower the cost per watt.
Roof limits sometimes decide for you. Panels on a north-facing or heavily shaded face may cost more than they save.

Quick estimates by use

These use our model's yields and 430 W panels, rounded up to whole panels.

Yearly use	Toronto	Calgary	Halifax
6,000 kWh	13 panels (5.6 kW)	12 panels (5.2 kW)	14 panels (6.0 kW)
9,000 kWh	20 panels (8.6 kW)	17 panels (7.3 kW)	21 panels (9.0 kW)
12,000 kWh	26 panels (11.2 kW)	23 panels (9.9 kW)	28 panels (12.0 kW)

Next step

Try your own numbers with our system size tool, or let us map the panels on your actual roof: check your roof.

Common questions

How many solar panels does an average Canadian home need?: It depends on your use and location. A home using 9,000 kWh a year needs roughly 17 to 21 panels of 430 W, depending on the city, using our model's yields.
How much roof space does one solar panel need?: A typical 430 W panel is about 2 square metres, or 21 square feet. Installers also leave clearances at edges, ridges and around vents, so plan for more than the panel area alone.
Should I size my system to cover 100% of my electricity use?: Not always. In Ontario, credits beyond your yearly use expire, and in net billing provinces exports earn less than you pay. The best payback is often at or a little below your yearly use.
Do I need more panels in winter?: You size for the whole year, not for winter. Under net metering, summer surplus credits cover darker months, so you don't need a system big enough to cover December on its own.

Sources

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