Free generator sizing calculator
What size generator do you actually need?
Select the essentials you want to keep running. We’ll estimate a practical backup-power range with headroom.
Headroom matters
Motors and compressors can draw extra power when they start.
Choose what must stay powered
Recommended shopping range
0 W
0 Wrunning load
0 Wlargest start-up adder
30%headroom
NEXT STEP
Generators that fit your result
Your recommended shopping range is shown above. Compare options close to this output, then verify continuous and surge ratings before buying.
Best matchSized around your result
More headroomFor extra appliances later
Check before buyingFuel type, outlets, transfer setup and surge rating.
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