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Generator run time and fuel calculator
How long will your generator run, and how much fuel do you need to store? Use the fuel use at your expected load from the manual.
Where to find the numbers
Manuals usually give the run time or fuel use at 25%, 50% and full load. A generator uses less fuel when lightly loaded, so running only what you need stretches your fuel. If your manual only gives hours per tank at a load, fuel per hour = tank size ÷ those hours.
Storing fuel safely
- Store fuel in approved containers, outdoors or in a detached shed, away from living areas and anything that could ignite it.
- Petrol (gasoline) goes stale; use a fuel stabiliser or rotate stored fuel.
- Turn the generator off and let it cool before refuelling — fuel spilled on a hot engine can catch fire.
- Run it outdoors only, more than 20 feet (6 m) from windows, doors and vents.
Working out what size you need? Try the generator wattage calculator.
For planning and general information. In an emergency, follow the instructions of your local authorities and call your emergency number (911, 112, 999 or 000).
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Source: arithmetic; safety from CDC, Carbon Monoxide Poisoning Basics.