If you just have a simple darkroom meter that can to calibrated to exposure times or negative densities (like the Ilford EM-10), then you might be interested in a free darkroom tool to download from my website.

You'll find the PaperGradeDial in my 'Library' section.

With only two disks required, the PaperGradeDial provides a quick method to calculate the overall paper contrast required to transfer the negative density range to the print density range. Using a densitometer or a simple darkroom timer, take a tonal shadow reading and set the negative density or the estimated exposure time on the dial. Then, take a tonal highlight reading, and next to its location on the dial, read off the required ISO paper grade to capture the entire tonal negative density range on paper. Note, the numbering system of variable contrast filers are only an approximation of ISO paper grades.