Generac standby generators come in 10kW, 14kW, 18kW, 22kW, and 24kW residential sizes. Picking the right one is mostly about which loads you want to keep running during a power outage.
The simple framework
Start with what you absolutely need during an outage, then work up.
10kW — essentials only
Heat, fridge, sump pump, freezer, well pump, internet, basic lighting, a few outlets, microwave at a time.
Best for: Small homes (under 1,500 sq ft), no central AC, you’re okay limiting load during the outage.
14kW — essentials plus some comfort
Everything in 10kW plus a small central AC, electric water heater, or a small electric range.
Best for: Mid-size homes (1,500–2,500 sq ft) with selective load shedding.
18kW — comfortable living during outages
Most of your home runs normally — AC, water heater, electric range, EV charger (slow). Some load shedding still helpful.
Best for: Larger homes (2,500–3,500 sq ft).
22kW — whole home, no compromise
Everything runs — multiple AC units, full electric kitchen, Level 2 EV charger, hot tub, electric water heater — without thinking.
Best for: Large homes (3,500+ sq ft), all-electric homes, homes with hot tubs / heat pumps / EVs.
24kW — specialty
For very-large homes (5,000+ sq ft) or homes with unusually high electrical loads (multiple heat pumps, three-car charging, commercial-grade kitchens at home).
What about gas line and transfer switch?
Bigger generators need bigger gas supply (1” vs 3/4” line) and bigger automatic transfer switches (100A vs 200A whole-house). We include all of this in the quote.
Quick rule of thumb
For most GTA homes — 18kW or 22kW. The 22kW is the easiest to spec, has the largest dealer network, and future-proofs for adding an EV charger or heat pump later. Worth the small step up.
Run our panel calculator to see your existing load, then start a generator quote for sizing recommendations.