Power Planning Calculator

Fuel Runtime Calculator

Estimate how long a stored fuel supply can operate a generator at a realistic load.

Planning estimate

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Enter your setup to calculate an estimate.

Your Setup

Use equipment labels or manufacturer specifications whenever possible.

1Fuel type

2Fuel available

gal

3Keep in reserve

Manufacturer runtime specification

Copy one runtime rating from your generator manual or product page at the load closest to your plan.

Test fuel amount

gal

Published runtime

hours

Published test load

Planning estimate

Enter your setup

–· Results update instantly.

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Enter your setup to see a practical planning estimate.

Load changes burn rate: A generator powering half its rated capacity usually consumes substantially less fuel than one near full load.
Usable fuel: Tank labels do not always equal safely usable capacity, especially for propane cylinders.
Storage limits: Fuel age, temperature, ventilation, and local storage rules all affect a safe outage plan.

Rule of thumb
Required fuel equals hourly burn rate multiplied by runtime, plus a reserve for changing loads.