Doors and trapdoors are 73/400 = 0.1825 blocks thick

The entity collision shapes for doors and trapdoors are 73/400 = 0.1825 blocks thick, even though they appear to be 3/16 = 0.1875 blocks thick. This applies to all of their block states. Other blocks that are meant to be 3/16 blocks thick are unaffected.

Steps to reproduce (Alternative 1)

1. Stand on a closed bottom trapdoor

2. Run the command /execute align y if entity @s[r=0,y=~0.1825]. The command succeeds, indicating that the height of the trapdoor is 0.1825 blocks.

A similar test can be done by standing against the other interior faces of a trapdoor or door and adjusting the test coordinate.

Steps to reproduce (Alternative 2)

1. Place a door or open trapdoor and a ladder adjacent to each other, so that they sit relatively flush with each other.

2. Walk into the centre of the door or trapdoor, and turn towards the ladder. The player will get stuck on the side of the ladder, indicating that the ladder is thicker than the door or trapdoor.

Expected behaviour

Doors and trapdoors should be 3/16 = 0.1875 blocks thick, matching their model and the powers of two that Minecraft uses for most other block shapes.