Standard ZDoom units

• distance – mapunits (also called mappixels)
• time – tics (or seconds in non-gameplay contexts)
• angle – turns counterclockwise

• velocity – mapunits per tic
• acceleration – mapunits per tic^2
• gravity – as acceleration

Gravity is defined by free fall acceleration, and is measured using the same units as normal acceleration.

These units should be converted to standard units before performing any operations with them.

• meters, feet, and other nonsense – Doom doesn't have an accurate scale
• sv_gravity units (800:1) – converted to acceleration by dividing by 800
• JumpZ units – see jumpz2height

• seconds (35:1)
• octics (4.375:1)

• degrees (360:1)
• radians (tau:1)
• byte angles (256:1)