[Suicide Junkie]

The number of "Standard movement" points is divided by the engines per move to get the actual movement (rounded down).

If the ship has at least one standard movement, then any of the "Bonus Movement" is added (not divided by engines per move).

In P&N, I used 1 EnginePerMovement per 50KT of ship size.

One thing to be wary of:
If a ship design is made with more than 255 "Standard Movement" points, then you will get a Range Check Error.
Human players can be expected to realize the problem and remove engines until the RCE goes away (the game will not crash), but you will need to keep an eye on AIs with large ships.