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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.

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Starting-watt calculator

Find the true startup surge for a motor or pump.

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NEC dwelling load calculator

Optional + standard service-load methods for a whole house.

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Size from your smart monitor

Use your real measured demand from a CSV export.

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Fuel & runtime

How long will it run?

Fuel-type comparison

Gas, propane, diesel, inverter, or battery side by side.

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Runtime calculator

How many hours a tank or battery lasts.

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Blackout runway timer

Live countdown of how long your fuel lasts.

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Altitude & temperature derating

How much output you lose to elevation and heat.

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Connect & run it safely

How do I hook it up?

Transfer switch & wire sizing

Safe switch amperage and wire gauge.

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Generator plug & inlet guide

The right NEMA connector and safe hookup path.

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Extension cord size & safety

The safe cord gauge for running power outdoors.

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Compare & decide

Which should I buy?

Generator vs. battery

Which fits your outages, budget, and loads.

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Generator cost of ownership

What a gas generator really costs over 5 years.

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EV charging on backup

Charge an EV alongside your home.

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Standby install quote

Get matched with local installers.

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