Wikipedia:
"The M4A3E2 Sherman "Jumbo" assault tank variant, based upon a standard M4A3(75)W hull, had an additional 38 mm (1.5 in) plate welded to the glacis, giving a total thickness of 101.6 mm (4.00 in), which resulted in a glacis of 148.97 mm (5.865 in) line-of-sight thickness, and over
180 mm (7.1 in) effective thickness. The sponson sides had 38 mm (1.5 in) thick plates welded on, to make them 76 mm (3.0 in) thick, a significantly thicker transmission casing, a new, more massive T23-style turret with 177.8 mm (7.00 in) of armor on the sides and rear and a 25.4 mm (1.00 in) thick flat roof, and a gun mantlet with an additional 88.9 mm (3.50 in) of armor welded on which resulted in a thickness of 177.8 mm (7.00 in). Intended for the assault to break out of the Normandy beachhead, it was originally to be armed with the 76 mm gun, but the 75 mm was preferred for infantry support and was used."
https://en.wikipedia.org/wiki/M4_Sherman#M4A3E2
Books put it around 175mm-180mm effective overall. Not that far from the King Tigers 185mm.