Calculate Ethanol % of Mixture


This calculator will calculate the octane and percent of ethanol from a mixture of E85/Ethanol and gasoline.
(one could use straight ethanol or even methanol, use appropiate octane rating)

Calculate Ethanol % of Mixture
Fuel Mix (Ex. E85)
GALLONS:
(E85) Octane:
% Ethanol:
Fuel Mix (Ex. E10)
GALLONS:
Gas Octane:
% Ethanol:
Input All Data, Please
The octane of E85 can be from 100 to 105 or so.
It is not a straight change with the addition of gasoline.
(100% ethanol around 115/120 octane, E85 is around 100/105 octane and it drops quickly after that)
It is suggested that 100 octane be used for E85 in this calculator to give a more accurate octane rating when mixed (diluted) with gasoline.