How Much Does It Cost to Run a Desktop Computer in Ontario? (2026)

Desktop power draw varies more than almost any other appliance. An office mini PC idles at 20 watts, while a gaming rig with a high-end graphics card can pull 500 watts or more under load.

A typical desktop computer (150 W) costs C$0.022 per hour, or about C$5.39 per month at 8 hours a day in Ontario. Average running cost

Hours used per day
WattagePer hourPer dayPer monthPer year
Low 60 WC$0.009C$0.072C$2.15C$26.21
Typical 150 WC$0.022C$0.18C$5.39C$65.52
High 500 WC$0.075C$0.60C$17.95C$218.42

Formula: watts ÷ 1000 × hours × price per kWh. Typical use is 8 h/day ≈ 438 kWh per year.

One hour of a desktop computer (0.15 kWh) is the same electricity as

Electricity per year at typical use, on a log scale: #69 of 95 appliances, from least to most.

In Ontario, with electricity at 15.0¢ per kWh (source: Hydro-Québec 2025 comparison, 2025-04), a typical desktop computer costs C$0.022 per hour and about C$65.52 per year at 8 hours a day. That is about 7% more than the national average for Canada (C$5.04 per month), because electricity in Ontario costs 15.0¢ per kWh against 14.0¢ nationally. Each C$1.00 of electricity buys roughly 44.6 hours of use.

How to lower the cost of running a desktop computer

In standby it draws about 2 W, which adds roughly 18 kWh (C$2.62) per year if it is never unplugged.

Is an efficient desktop computer worth it?

Desktop PC with monitor for office work, about 150 W: about 438 kWh a year. Laptop for the same work, about 45 W: about 131 kWh. The difference is worth C$45.93 a year in Ontario.

Usage assumed: 8 hours a day. Typical prices: C$900.00 for the efficient model, C$900.00 more than a basic one. Work it out with your own prices

Frequently asked questions

How many watts does a gaming PC use?

Between 300 and 600 watts while gaming, depending on the graphics card. Idle draw is typically 50 to 100 watts.

Does leaving the PC on overnight cost a lot?

At 60 watts idle for 12 hours it uses 0.72 kWh, roughly the cost of a few minutes of a space heater.

Does a bigger power supply use more electricity?

No. The PSU only delivers what the components request. A larger unit just has more headroom.

Compare with

Cost by region

US states
Canadian provinces

Related appliances

Use the generic electricity cost calculator · Which uses more? Take the quiz