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 appropriate octane rating)

The Octane Rating in the calculator is using (R+M)/2 values.
You can use your octane value (like RON), the answer will be in your octane value.

Calculate Ethanol % of Mixture
Fuel Mix
GALLONS:
(Ethanol) Octane:
% Ethanol:
Fuel Mix
GALLONS:
Gas Octane:
% Ethanol:
Input All Data, Please
The equivalent octane of E85 can be from 105 to 109 or so.
The equivalent octane of 100% ethanol is around 113-115.
(there is no 'octane' additive like in gasoline, in ethanol or methanol)