Generator Runtime Calculator
Estimate generator runtime, usable fuel, delivered electrical energy and operating cost from tank size and measured fuel consumption.
Default project preview
9.6 hours
Delivered energy per usable tank
43.2 kWh
Fuel cost per hour
$2.81
Usable-tank fuel cost
$27.00
Fuel for planned period
9 gal
Calculator
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Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Usable fuel = tank capacity × (1 − reserve). Runtime = usable fuel ÷ fuel consumption per hour. Delivered energy = runtime × average electrical load. Operating cost uses fuel consumption and price.
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FAQ
Generator Runtime Calculator questions
Why enter fuel consumption instead of only generator size?+
Generators of the same rating can use different amounts of fuel, and consumption changes substantially with load.
What reserve should be used?+
A reserve accounts for unusable fuel, gauge uncertainty and avoiding a completely dry tank. Use a value appropriate to the equipment.
Does this calculate safe generator capacity?+
No. Use a generator-sizing and electrical-load calculation to verify starting loads, continuous rating and connection method.