It seems that both Mr. Malty and YeastCalc base their growth rates and cell counts on data produced by the same experiment at White Labs.
Does anyone know of another source of data correlating starter size to yeast populations? Perhaps experiments they have done themselves?
Last weekend I sat down with my brother, a microbiologist, and counted cells in four of my saved slurries with a hemocytometer and was surprised to find a huge discrepancy between the yeast calculators and my cell counts. Albeit this is the first time I have counted cells, and White Labs has been doing it for decades, so I think I know where the source of error lays. However, I would be curious to hear what others have found.
Here is a blog post on the subject