Okay, going by WWII Ballistics: Armor and Gunnery, I'll calculate effective thickness of both the Tiger's and Sherman's glacis. The equation for 0 degree equivalent is as follows:

T * F * (T/D)^G

Plug in the numbers, and you'll get your equivalent thickness. You'll also need to know A for overall impact angle, L for lateral angle and V for vertical angle. The full equation for the 0 degree equivalent of the Tiger's glacis is as follows:

100 * 2.71828 ^ (0.0000408 * 0.998 ^ 2.5) * (100/75) ^ 0.0101 * 2.71828 ^ (0.1313 * 0.998 ^ 0.8)

And the result is as follows:

114.34mm of effective armor against 75mm APCBC and APC.

Now for the Sherman (late model with the 47 degree glacis):

64 * 2.71828 ^ (0.0000408 * 0.999 ^ 2.5) * (64/75) * 0.0101 * 2.71818 ^ (0.1313 * 0.999 ^ 0.8)

However, due to the Sherman having a sloped glacis plate, slope effects come in to play.

Slope effect equation for the Sherman's glacis is as follows:

a * (T/D)*b

where a is 1.7933, T is 64mm, D is 75mm, and b is 0.1655

Result for the slope modifier is as follows:

1.75

Take the 0 degree equivalent thickness (72.86) and multiply it by the slope modifier.

Result is as follows:

127.3mm effective against 75mm APCBC and APC.