Generator Calculators and Tools
Last updated:ByStandby Power Desk
Every calculator here works from a published figure with its source named on the row, and every one gives you an answer without asking for an email address. Where two sources disagree Home Generator Index keeps both ends and widens the range rather than picking a favourite, which is why the results are ranges and not single numbers.
Sizing and load
Generator sizing calculator
What size generator do I need?
Tick your appliances. A furnace, fridge, sump pump and lights come to about 5,900 W and fit a 10 kW unit; add a 3-ton air conditioner and the same house needs 26 kW.
Open the toolAppliance wattage chart
How many watts does a refrigerator use?
A fridge is 132 to 600 W running and 1,200 to 2,800 W to start. Running and starting watts for 23 appliances, with the published source on every row.
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What it costs
Home generator cost calculator
What does a home generator cost?
A 14-18 kW standby generator is $9,500 to $13,000 fully installed in Toronto. Add a 100 A panel or a gas run past 60 ft and watch what it does to the total.
Open the toolTransfer switch cost calculator
What does a transfer switch cost?
An automatic switch is $1,500 to $3,000 installed, a manual one $800 to $1,500, an interlock kit $400 to $800. Permit included, double-counting excluded.
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Running costs
Fuel running-cost calculator
What does a generator cost to run?
A 22 kW unit burns 6.46 m3 an hour at half load: about $43 of Enbridge gas for a 24-hour outage, against roughly $161 on propane.
Open the toolPropane consumption calculator
How much propane does a generator use?
A 22 kW unit burns 9.57 L an hour at half load, so a 500-gallon tank's 1,514 usable litres last about 6.6 days. Load moves that by more than two days.
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Worth it?
Standby or portable picker
Standby or portable generator?
Five questions, then a verdict with every point it awarded. Legal portable hookup is $900 to $2,300; a 14-18 kW standby is $9,500 to $13,000 installed.
Open the toolBattery vs generator runtime
Home battery or generator?
A 13.5 kWh battery on a 1,500 W load lasts 9 hours; a generator on the gas main does not run out. Includes the Ontario rebate condition most pages leave out.
Open the toolOutage cost calculator
What does a power outage cost?
Health Canada gives a fridge 4 hours and a full freezer 48. Apply those to your own numbers and get the annual figure to hold against a generator.
Open the toolWorth-it checker
Is a whole house generator worth it?
Ten years all in is $11,900 to $18,000. Payback needs outages costing over $1,200 a year, and this tool will tell you when the answer is no.
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How the numbers on these tools are sourced
Prices come from named Canadian contractors, utilities and government pages, quoted in Canadian dollars and dated. Equipment figures such as fuel consumption come from the manufacturer's own published spec sheet rather than a reseller's summary of it. Where a figure genuinely is not published anywhere in Canada, the tool takes it as an input from you and says so on the page instead of shipping an invented average. Each tool lists its own sources at the foot of the page.
Prices exclude the 13 percent HST unless a row says otherwise, and none of these tools is a quote. The cost guides break a real quote into its line items, and the methodology page sets out what this register does and does not check.