Base builder
Fortifications in real metres — the game's own: a Bremmer Wall stands 5.09 m tall, a Recon Tower 7.6 m, the FOB mast 13.07 m. Lay out the perimeter, look at it from above or stand inside it at eye height, and count not just supplies but how many trips it takes to carry there.
Where the numbers come from
Sizes are the game's collision boxes
Each footprint is the piece's collision box — not a guess off a render, but the volume that actually stops a body. That is why the tower is 6 × 6 at 7.6 m tall, and a Bremmer Wall is a 1.5 × 1.5 block over five metres high rather than the low strip we assumed. One exception: the gate's collision box is a metre and a half taller than the gate, because it includes the swing, so we take its visible bounds instead. It all lives in the database, and the change log shows what we corrected.
The limit is trips, not supplies
A Bremmer Wall does not stack: forty walls are forty inventory slots that somebody has to physically bring. That is why the manifest has a line about slots — it is usually what decides whether the perimeter gets built at all.
The piece card shows two costs separated by a slash. The game data holds two figures and they disagree — a wall is 15 or 13 depending on the field. Which one the game actually spends is not visible in the data, so we show both instead of choosing for you.