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 |
| regular crate small teleporter gate |
64 units | 1.5 m | 4.9 ft |
| big door 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 |
| medium-size room 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 |