Torch spacing for spawn-proofing: the exact number, not a guess
Hostile mobs need block light 0. Torches emit light 14 and lose 1 per block. That gives a precise grid — and a different answer for floors, ceilings and open builds.
Most spawn-proofing advice is "put torches every 7 blocks or so". The real rule is tighter than that in some places and looser in others, and it comes from two numbers.
The two numbers
- Hostile mobs spawn at block light level 0 in Java Edition. Not 7 — zero. That
changed in 1.18 and a lot of older guides never caught up.
- A torch emits block light 14 and it drops by 1 per block of taxicab distance
(|dx| + |dy| + |dz|), not straight-line distance.
So a torch keeps light above 0 out to 13 blocks of taxicab distance. Anything at 14 or beyond is back to 0 and can spawn.
Flat floor: the diamond, not the square
Because distance is taxicab, a torch's coverage is a diamond, not a circle or a square. On a flat floor the safe pattern is torches on a diagonal lattice.
In practice, placing torches in a plain grid every 12 blocks covers a floor with margin for error. Tighten to every 9 if the surface has slabs, stairs or any block that eats a light level.
Height costs the same as distance
This is the part people miss. A torch on a wall at eye height is already spending light levels on the vertical gap before it reaches the floor. A torch 2 blocks up covers 2 fewer blocks in every horizontal direction.
For a mob farm perimeter or a cave floor, put the torch on the floor, not on the wall.
Where the rule changes
- Bedrock Edition still spawns hostiles at light level 7 and below, so it needs
roughly half the spacing. Java's light-0 rule does not transfer.
- Slabs, stairs, carpets — the top surface must be a full block for most hostiles.
Bottom slabs are cheaper than torches over a large flat area.
- Blue ice, packed ice, glass are not valid spawn surfaces at all.
Cheaper than torches
For a big open area, light is the expensive way. Non-spawnable surfaces cost nothing to maintain and never get griefed by water:
| Method | Cost | Note |
|---|---|---|
| Torch grid | 1 coal + 1 stick per torch | needs re-lighting after water |
| Bottom slabs | ½ block each | permanent, no light needed |
| Carpet | 2 wool per 3 | cheap, but burns |
Enter your build's dimensions and light sources in the Spawn Proofing Calculator — it applies the exact Java block-light rule and returns the grid, rather than a rounded rule of thumb.