[2] This lichen species forms a corticolous thallus that can be continuous or marginally dispersed into rounded, confluent patches.

The thallus measures up to 30 mm (1+1⁄5 in) across and 20–40 μm thick, displaying a smooth, pale grey to greenish-grey colour.

The apothecia are rounded, measuring 0.4–1 mm in diameter and 250–350 μm high, with a grey-black disc and a distinct white pruina.

[2] The ascospores of Calopadia cinereopruinosa are single, oblong to ellipsoid in shape, muriform, and colourless, measuring 45–80 by 15–25 μm.

[2] Calopadia saxicola, a saxicolous (rock-dwelling) species growing on rocky seashores in southern Brazil, also has pruinose apothecia and muriform ascospores.