The coordinates and dimensions of objects in Doom levels are generally described by integer values between -32768 and +32767. The unit length is often called a map unit (or simply, unit). Each unit is proportional to 1 pixel of a texture or sprite.
It is difficult to translate the size of a Doom map unit into a real-world unit, since the dimensions of various objects in the game are inconsistent. Very roughly, one could attempt to translate 32 map units as 1 meter (3.28 feet) based on the height of the Doom guy. Due to aspect ratio correction, the width of objects would be 0.75 m (2.4 ft) each 32 units. With this interpretation, the Doom guy would be 1.75 m (5.7 ft) tall and the smaller doors 2.25 m (7.3 ft) tall.
Some example dimensions in terms of Doom's map units are:
|Structure||Map unit||Real Life Unit|
|small map details such as support beams and wall lamps||16 units||37 cm||1.2 ft|
|smallest gap the player can pass through||32 units||75 cm||2.4 ft|
small teleporter gate
|64 units||1.5 m||4.9 ft|
width of regular corridor such as the main hallway in MAP01: Entryway (Doom II)
|128 units||3 × 4 m||9.8 × 13.1 ft|
|small room||200 units - 400 units||4.6 - 9.3 m||15.3 - 30.7 ft|
start room of E1M1: Hangar (Doom)
|500 units - 800 units||11.7 - 18.7 m||38.4 - 61.5 ft|
|Final boss||768 units × 384 units||18 × 12 m||59 × 39.3 ft|
|large room such as the Spider Mastermind room in MAP06: The Crusher (Doom II)||800 units - 1500 units||18.7 - 35.1 m||61.5 - 115.3 ft|
|typical Doom level (Knee-Deep in the Dead)||4000 units||93.7 m||307.5 ft|