B20 compression ratio math
 

https://docs.google.com/spreadsheets...it?usp=sharing

Above is a link to view my google spreadsheet I made to calculate the compression ratio of a b20z with ycp pistons (type r copies in 84mm bore), a b16a head, 0.029" head gasket, stock crank and rods.
I compared this ratio to a compression ratio calculator and the numbers were fairly close, but not the same. I got 11.5 using my measured/researched measurements on the following calculator
http://www.zealautowerks.com/bseries.html
So their is only around a 0.1 compression ratio difference, possibly just different rounding (number of bits for a float) for each program?
I believe this to be accurate, however I would love to get some feedback on my calculations.