Which is larger the red sea or the black sea?

The Red Sea is slightly bigger.

Red Sea covers an area of 438,000 km2 (169,100 sq miles), has a depth of 2,211 metres (7,254 feet).

Black Sea covers an area of 436,400 km2 (168,495 sq miles), and has a depth of 2,206 meters, (7,238 feet).