Flex Fuel Mixing Tool
Ethanol Blend Calculator
Work out exactly how much E85 to add to hit a target ethanol percentage, or check the resulting blend from a mix you’ve already made.
E0
Ethanol content
Current tank
gal
%
Fuel to add
%
E85 pump ethanol content legally varies 51–83% by season/region — adjust if you know your station’s actual rating.
%
gal
Fuel A (already in tank)
gal
%
Fuel B (added)
gal
%