South Sudan covers 623,998 km² km² on the new Equal Earth world map — 0.5%% of all land on Earth, making it the 43rd largest country in the world and the 18th largest in Africa. At 7° latitude Mercator only inflates South Sudan by about 2%%, so the old and new maps largely agree on it — unlike the far north, where Mercator's stretch is dramatic.
For scale: South Sudan is roughly the same size as France (635,064 km² km²).
You could fit 3 of Tunisia inside South Sudan.