Short answer: square footage is not enough information
Two houses with 2,000 square feet of conditioned space can have different backup requirements because one may use gas heat and city water while another uses a heat pump, electric resistance backup heat, electric water heating, and a well pump. Even similar homes can have different central-air conditioner models, motor-start requirements, and outage priorities.
We do not map a floor area to a generator size or automatically recommend a model. Use this page to identify what changes the load, collect the equipment data, and discuss it with a qualified local professional.
Three 2,000-square-foot homes with different load questions
| Illustrative home profile | Information that may matter | What a professional must verify |
|---|---|---|
| Gas furnace, city water, one central AC | AC model and starting data; furnace fan; refrigeration; selected kitchen and lighting loads. | Which circuits must run together, HVAC startup, and whether loads can be sequenced or managed. |
| Heat pump with electric auxiliary heat, electric water heater | Compressor operation, auxiliary strip stages, water heating, and other large electric loads. | Actual controls and nameplate demand; whether auxiliary loads can be safely excluded or controlled during backup. |
| Gas heat, well water, sump pump, central AC | Pump motor starts, AC starts, and which loads may overlap. | Pump and HVAC model data, start sequence, transfer equipment, and load-management design. |
These profiles are examples of questions to investigate, not measured homes or capacity recommendations.
What to collect before requesting a quote
- Heating and cooling system manufacturer, model, voltage, full-load amperage, and starting/locked-rotor information if published.
- Well, sump, sewage, or other pump make/model and electrical nameplate data.
- Electric water heater, range, dryer, EV charger, and other large loads you want to run.
- Which loads are essential and which could be delayed, shed, or excluded during an outage.
- Fuel available at the property, panel/service configuration, equipment locations, and any site restrictions.
Photograph the equipment labels and keep the corresponding owner manuals. A general wattage chart is for orientation only; nameplate and installation data take precedence.
Approximate equipment ranges can illustrate why the answer varies
Champion Power Equipment's current household chart lists a 3-ton central AC at 3,000–3,500 running watts and 5,000–6,000 starting watts; a 1/2 HP well pump at 750–1,000 running watts and 1,500–2,000 starting watts. These are that manufacturer's generalized reference ranges, not ratings for any particular 2,000-square-foot home. A different appliance label/manual may show substantially different data.
Use the full appliance wattage chart only to prepare questions. Do not add every starting number and treat the result as a generator recommendation. A professional must check coincident running loads, motor starts, selected circuits, fuel-specific output, transfer equipment, and site conditions.
Get a site-specific assessment before choosing capacity
Ask the installer to show the exact generator model and its rating on the planned fuel, the selected transfer switch, backed-up circuits, any load-management devices, and the motor-start assumptions. Ask what fuel-line, electrical, panel, placement, permit, and commissioning work is included.
A current Generac example illustrates why fuel matters: model G0073270 is listed at 26 kW on LP and 24 kW on natural gas. That is the manufacturer rating for that model—not proof that a 26 kW unit fits a particular floor plan. Read our load-based sizing guide and the linked model’s current spec sheet, then have the complete system evaluated professionally.
For cost context, see our standby cost guide; for the installation sequence, see what to expect during installation.