Three Ways to Decide
| Approach | What runs | Effect on size |
|---|---|---|
| Essentials only | Refrigerator, freezer, furnace fan, sump pump, some lights and outlets, internet | Smallest unit, often a smaller transfer switch |
| Whole house with load management | Everything, but big loads like AC or a dryer are shed or staggered automatically | Mid-size unit covers more than its rating suggests |
| Whole house, all at once | Every appliance running together, including central AC | Largest unit and highest fuel use |
Loads That Drive the Size Up
- Central air conditioning. A compressor draws a surge when it starts. Many Broken Arrow outages happen in summer storms, so decide early whether AC is on the list. Soft-start kits on the condenser can reduce the surge; ask about them.
- Electric heat or heat pump backup strips. Resistance heat strips are very large loads. Homes with gas furnaces have it easier, because the generator only runs the blower.
- Electric range, dryer and water heater. These can be powered, but usually with load management.
- Well pumps on acreages east and south of town also have a starting surge.
- Medical equipment. List it with the installer so those circuits are never shed.
Published Prices by Size
| Size | Unit only (HomeGuide) | Installed, natural gas (HomeGuide’s natural gas generator guide) |
|---|---|---|
| 13–16 kW | $3,000–$4,500 | $6,000–$10,000 |
| 17–20 kW | $4,000–$6,000 | $7,000–$11,000 |
| 22–25 kW | $4,500–$12,000 | $9,500–$24,000 |
| 30–48 kW | $10,000–$16,000 | not listed |
Size ranges and prices are national figures from HomeGuide, checked Nov 4, 2026. They are not recommendations for your house.
What a Proper Sizing Visit Includes
A careful installer walks the panel, notes each appliance and its nameplate, asks about heat type and medical needs, and does a load calculation. Be wary of a size chosen only from square footage over the phone. Ask for the calculation in writing, and ask which loads (if any) will be managed.
Write Down Before the Visit
- Heat type: gas furnace, heat pump, or electric
- How many AC units and their tonnage if you know it
- Electric or gas range, dryer and water heater
- Panel amperage (on the main breaker)
- Anything medical
Request a Generator Installation Quote
Answer two quick questions. An independent installer that serves Broken Arrow will contact you to schedule a site visit and a written estimate.
Please note: Broken Arrow Generators connects homeowners with independent local generator installers. We are not a contractor and do not do the work.