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All calculators
Every tool for sizing & running backup power
16 calculators on one surge-accurate engine — from what size do I need to how long will it run to what cord is safe.
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Whole-home load sizer
Add your real appliances and the calculator sizes a generator or battery on the surge-accurate peak — running watts plus the single largest startup surge, the moment that actually trips a unit.
Open the load sizer →Size your backup power
What size do I need?What can my generator run?
Flip appliances on a live breaker-box gauge.
Starting-watt calculator
Find the true startup surge for a motor or pump.
NEC dwelling load calculator
Optional + standard service-load methods for a whole house.
Size from your smart monitor
Use your real measured demand from a CSV export.