Size comparison
18 kW vs 20 kW generator
Two adjacent whole-house sizes. The bigger unit covers more load; the smaller one costs less to buy and run. Here's how to choose between them.
Side by side
| Spec | 18 kW | 20 kW |
|---|---|---|
| Typical use | Critical systems for 1,500–3,000 sq ft | Main systems for large homes, 3,000–5,000 sq ft |
| Unit price (our catalog) | $5,379–$6,769 | $5,813–$6,782 |
| Models in catalog | 2 | 3 |
| Installed cost page | See 18 kW cost | See 20 kW cost |
Which one?
The 20 kW steps up to the next load class, useful if you're adding a second AC, a well pump, or an electric dryer to the backup. The 18 kW keeps the unit and install smaller and cheaper. If you're between them, run our sizing calculator on your actual loads before paying for the extra capacity.
Models at each size
Still choosing a size? Run the sizing calculator
Wondering what it costs? See the cost hub
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