Calculating the crosswind is the sinus function of the wind angle, therefore another way to simply figure out crosswind is to know 4 sinus numbers. The 4 sinus numbers of 30, 50, 60, and 80 degrees.
sin30 = .5 (with a wind from 30 degrees the cwc is half the total wind)
sin50 = .75 (with a wind from 50 degrees the cwc is 3/4 the total wind)
sin60 = .9 (with a wind from 60 degrees the cwc is the total wind minus 10%)
sin80 = 1.0 (any wind of more than 80 degrees and your cwc is the total wind)
But by far the easier is the clock method