Digital Mini Toolbox

Compression Ratio Calculator

When building a performance Classic Mini engine one of the most important figures to determine is the compression ratio. Using the Classic Mini DIY Compression Ratio Calculator below, you can determine the ideal compression for your new engine build.

Please choose a value between 0 and 20

Please type a decimal value between 15 and 35

Please choose a value between 0 and 80


Please note the above figures are approximate values. Before purchasing parts and building your engine we recommend doublechecking your calculations multiple times using more than one source. The mathematical equations used in this tool can be found here: Equation Source Code

Alternate Source: Calver Compression Ratio, JE Pistons Compression Ratio