I don't know but this site says...
http://snapsort.com/compare/Canon_EOS_5D_Mark_II-vs-Canon_EOS_7D
"Significantly larger viewfinder 0.71x vs 0.62x More than 30% larger viewfinder"
and this bloke says...
http://www.bobatkins.com/photography/digital/eos7D_vs_50D_vs_5DII.html
Viewfinder
The EOS 7D has a 100% 1x optical viewfinder. The 50D has a 95% 0.95x viewfinder and the 5D MkII has a 98% 0.71x viewfinder. From these numbers you might think that the 7D has the largest viewfinder, but if you did, you'd be wrong. You have to take format size into account. In fact the relative viewfinder screen size you see when looking through the viewfinder is given by (coverage x magnification)/(digital multiplier factor). The digital multiplier factor for APS-C is 1.6x and for full frame is 1x. So the relative viewfinder sizes are:
•EOS 7D - 0.62
•EOS 50D - 0.56
•EOS 5D MkII - 0.7
So the 7D viewfinder is about 10% larger than that of the 50D, but about 12% smaller than the 5D MkII
but I wonder if it matters? When I use my 20D I never notice anything wrong