Home › Generator Sizing Guide
Pricing reviewed October 2026
| Home need | Generator size | Installed cost |
|---|---|---|
| Essentials only | 10–14 kW | $6,000 – $10,000 |
| Most homes | 18–26 kW | $10,000 – $15,000 |
| Large / all-electric homes | 26+ kW | $15,000 – $25,000 |
Add the running watts of what you need, add starting-surge headroom for motors (A/C, well pumps), and add 20–25% margin.
Know your size? Price it with the home generator cost calculator · Compare brands: Kohler vs. Generac.
Generator figures marked as from the 2026 cost guide (whole-house generator $6,000–$25,000 installed, typically $10,000–$15,000; unit $3,000–$6,000; installation $3,000–$5,000; 10–14 kW $6k–$10k, 18–26 kW $10k–$15k, 26+ kW $15k–$25k) come from the HomeGeneratorCost 2026 guide. Add-on ranges, load wattages and city factors are editorial estimates. Get written quotes from licensed installers.