Ethanol Blending Calculator

Ethanol Blend Calculator — E85 Mix Tool
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
Ethanol percentages for pump E85 vary by season and region (ASTM D5798 allows roughly 51–83%). This tool gives a mixing estimate — confirm your actual E85 rating with a flex-fuel sensor or gas analyzer before tuning to it.
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