Generator Sizing Guides
Start with the question you already have — your house size, A/C tonnage, appliance or generator class — then use the main calculator to combine the loads for your actual home.
Home size
What Size Generator for a 1,000 Sq Ft House?
10–18 kW
Read guide →Home sizeWhat Size Generator for a 1,200 Sq Ft House?
12–18 kW
Read guide →Home sizeWhat Size Generator for a 1,500 Sq Ft House?
14–22 kW
Read guide →Home sizeWhat Size Generator for a 1,800 Sq Ft House?
14–22 kW
Read guide →Home sizeWhat Size Generator for a 2,000 Sq Ft House?
18–26 kW
Read guide →Home sizeWhat Size Generator for a 2,200 Sq Ft House?
18–26 kW
Read guide →Home sizeWhat Size Generator for a 2,500 Sq Ft House?
20–28 kW
Read guide →Home sizeWhat Size Generator for a 3,000 Sq Ft House?
22–30+ kW
Read guide →Home sizeWhat Size Generator for a 3,500 Sq Ft House?
24–36+ kW
Read guide →Home sizeWhat Size Generator for a 4,000 Sq Ft House?
26–40+ kW
Read guide →Home sizeWhat Size Generator for a 5,000 Sq Ft House?
30–48+ kW
Read guide →HVAC
Generator Size for 2-Ton Central A/C
about 2.5 kW running / 7 kW startup
Read guide →HVACGenerator Size for 2.5-Ton Central A/C
about 3.2 kW running / 8.5 kW startup
Read guide →HVACGenerator Size for 3-Ton Central A/C
about 4 kW running / 10 kW startup
Read guide →HVACGenerator Size for 3.5-Ton Central A/C
about 4.5 kW running / 11.5 kW startup
Read guide →HVACGenerator Size for 4-Ton Central A/C
about 5.2 kW running / 13 kW startup
Read guide →HVACGenerator Size for 5-Ton Central A/C
about 6.5 kW running / 16 kW startup
Read guide →HVACGenerator Size for Two Central A/C Units
sum both running loads + the larger startup increment
Read guide →HVACGenerator Size for a Heat Pump
roughly 3–7 kW running; startup varies widely
Read guide →HVACGenerator Size for Electric Resistance Heat
often 5–20+ kW depending on strips/zones
Read guide →Generator size
What Can a 10 kW Generator Run?
10 kW
Read guide →Generator sizeWhat Can a 14 kW Generator Run?
14 kW
Read guide →Generator sizeWhat Can a 18 kW Generator Run?
18 kW
Read guide →Generator sizeWhat Can a 20 kW Generator Run?
20 kW
Read guide →Generator sizeWhat Can a 22 kW Generator Run?
22 kW
Read guide →Generator sizeWhat Can a 24 kW Generator Run?
24 kW
Read guide →Generator sizeWhat Can a 26 kW Generator Run?
26 kW
Read guide →Generator sizeWhat Can a 28 kW Generator Run?
28 kW
Read guide →Generator sizeWhat Can a 30 kW Generator Run?
30 kW
Read guide →Comparisons
14 kW vs 18 kW Generator
+4 kW difference
Read guide →Comparisons18 kW vs 22 kW Generator
+4 kW difference
Read guide →Comparisons20 kW vs 22 kW Generator
+2 kW difference
Read guide →Comparisons22 kW vs 24 kW Generator
+2 kW difference
Read guide →Comparisons22 kW vs 26 kW Generator
+4 kW difference
Read guide →Comparisons24 kW vs 26 kW Generator
+2 kW difference
Read guide →Comparisons26 kW vs 30 kW Generator
+4 kW difference
Read guide →Appliances & loads
Generator Size for a Refrigerator
about 700 W running / 2,200 W startup
Read guide →Appliances & loadsGenerator Size for a Freezer
about 500 W running / 1,500 W startup
Read guide →Appliances & loadsGenerator Size for a Sump Pump
about 1,050 W running / 2,150 W startup
Read guide →Appliances & loadsGenerator Size for a Well Pump
about 1,500 W running / 4,500 W startup for a representative residential pump
Read guide →Appliances & loadsGenerator Size for an Electric Water Heater
about 4,500 W running / 4,500 W startup
Read guide →Appliances & loadsGenerator Size for a Gas Furnace Blower
about 800 W running / 2,300 W startup
Read guide →Appliances & loadsGenerator Size for a Pool Pump
about 1,500 W running / 4,500 W startup
Read guide →Appliances & loadsGenerator Size for An Ev Charger
about 7.7 kW for a common 32-amp Level 2 charging rate
Read guide →Appliances & loadsGenerator Size for an Electric Range
roughly 3–8+ kW depending on burners and oven use
Read guide →Appliances & loadsGenerator Size for an Electric Clothes Dryer
about 5,000 W running / up to roughly 5,750 W startup
Read guide →Appliances & loadsGenerator Size for a Garage Door Opener
about 875 W running / 2,350 W startup
Read guide →Appliances & loadsGenerator Size for a Septic or Sewage Ejector Pump
roughly 800–1,500 W running / 2,000–4,500 W startup
Read guide →Appliances & loadsGenerator Size for a Hot Tub or Spa
roughly 5–11+ kW depending on heater and pumps
Read guide →Appliances & loadsGenerator Size for a Home Office
roughly 500–1,500 W for computers, networking and monitors
Read guide →