Armour against aircraft bombs

How much armour is needed to protect a carrier from bombs?

There is no single thickness: protection standards, bomb size, deck location, and stability all matter, though larger bombs require more armour.

There is no single armour thickness for 500-, 1,000-, or 2,000-pound bombs. Required protection changes with whether the aim is to stop some, most, or effectively all penetrations. Armour location matters because heavy protection placed high on a carrier reduces stability through its effect on metacentric height. The Illustrious class provides practical context, while larger bombs demand progressively heavier protection.