Generator Fuel Storage Calculator

Determine fuel storage needs for backup generators based on load, consumption rate, and desired runtime.

Nameplate kW rating of the generator set.
kW
Percentage of rated capacity actually used. Typical DC load factor: 70-80%.Operating below 30% is harmful.
%
Target backup runtime in hours. 24-72 hrs typical. Some codes require specific minimums.
hours
Diesel consumption at full load. Typical: 7 gal/hr per 100 kW. Or use manufacturer spec.
gal/hr per 100kW
Size of on-site fuel storage tank. Enter 0 to calculate required tank size.
gallons

Results

Actual Load:
Generator capacity x load factor.
-kW
Fuel Consumption Rate:
Actual fuel burn rate at operating load.
-gal/hr
Fuel Required for Target Runtime:
Total fuel needed for the specified runtime.
-gallons
Tank Sufficient:
Whether existing tank can hold required fuel.
-
Days of Runtime (with tank):
How many days the existing tank provides at operating load.
-days
Hours of Runtime (with tank):-hours
Daily Fuel Consumption:-gal/day
Fuel Cost Estimate (@$4/gal):
Estimated fuel cost for the target runtime.
-
Reference: NFPA 110 (Emergency and Standby Power Systems). Typical diesel consumption ~7 gal/hr per 100 kW at full load. Derate consumption linearly with load factor.