Factorio modules and beacons, with real numbers
Every panel in game shows you a percentage of something. What they do not show is how the numbers combine — and three of the rules below are the ones players get wrong most often: a beacon cannot transmit productivity at all, a stone furnace cannot hold a module, and only 31 of the 180 recipes here accept productivity modules.
The whole formula
For one machine, with every module slot filled and n beacons covering it:
items per minute = (60 / craft time)
× items per craft
× machine speed
× (1 + module speed + beacon speed)
× (1 + productivity)
beacon speed = √n × 1.5 × (modules per beacon × module speed)The √n is the part that surprises people. Each beacon's transmission strength is 1.5 / √n, so n beacons add up to a total of √n × 1.5 times one beacon's worth. Ten beacons are not ten times one beacon — they are 3.16 times one beacon.
Productivity behaves differently: it multiplies output per craft, which means a machine with +40% productivity needs fewer machines for the same output and fewer inputs upstream. Both effects cascade down the whole tree, and that is why the tables below show raw material dropping too.
Worked example: 60 iron gear wheels per minute
Assembling machine 3 (speed 1.25), 4 productivity module 3 (+40% productivity, −60% speed from the modules themselves), 8 beacons each holding 2 speed module 3:
- Base output: (60 ÷ 0.5 s) × 1 × 1.25 = 150/min per machine
- Beacon speed: √8 × 1.5 × (2 × 0.5) = +424%
- Total speed multiplier: 1 − 0.6 + 4.243 = 4.64×
- Output per machine: 150 × 4.64 × 1.4 = 975/min
- 60/min therefore needs 0.06 machines — one machine covers a full gear line, and the iron plate it eats drops from 120/min to 85.7/min because of the productivity.
That last number is the one worth internalising: productivity does not only help your output, it shrinks everything upstream of it.
Beacon stacking: what each extra beacon actually gives you
8 beacons holding 2 speed module 3 each. "Transmission" is the factor each individual beacon applies to its modules.
| Beacons | Transmission each | Total speed bonus | Gain from this beacon | Bonus per beacon |
|---|---|---|---|---|
| 1 | 1.500 | +150% | +150% | +150% |
| 2 | 1.061 | +212% | +62% | +106% |
| 3 | 0.866 | +260% | +48% | +87% |
| 4 | 0.750 | +300% | +40% | +75% |
| 6 | 0.612 | +367% | +32% | +61% |
| 8 | 0.530 | +424% | +27% | +53% |
| 10 | 0.474 | +474% | +24% | +47% |
| 12 | 0.433 | +520% | +22% | +43% |
The first beacon is worth +150% speed on its own; the twelfth adds only +22%. That curve is why beacon-heavy builds are space-hungry: past eight beacons you spend a lot of room for a small gain, and the machine count barely moves.
A building can only be covered by a limited number of beacons: 12 for 2×2 to 4×4 machines (so every assembling machine, furnace, chemical plant and centrifuge) and 16 for 5×5 machines such as the oil refinery.
Module slots per machine
| Machine | Speed | Module slots | Productivity allowed | Max beacons |
|---|---|---|---|---|
| Assembling machine 1 | 0.5 | 0 | no | — |
| Assembling machine 2 | 0.75 | 2 | yes | 12 |
| Assembling machine 3 | 1.25 | 4 | yes | 12 |
| Stone furnace | 1 | 0 | no | — |
| Steel furnace | 2 | 0 | no | — |
| Electric furnace | 2 | 2 | yes | 12 |
| Chemical plant | 1 | 3 | yes | 12 |
| Oil refinery | 1 | 3 | yes | 16 |
| Centrifuge | 1 | 2 | yes | 12 |
Both furnaces at the cheap end of the game — stone and steel — have zero module slots. They cannot hold modules and, because beacon effects only reach buildings that have module slots, they cannot be boosted by beacons either. If you want modules in your smelting, the electric furnace is the first one that accepts them.
Assembling machine 1 is in the same position: zero slots. A tier-1 assembler ignores every beacon you build around it.
Which recipes actually accept productivity
Productivity modules are restricted to intermediate products. Of the 180 recipes in this calculator, 31 allow them and 149 do not. A productivity module placed in a machine making a finished building still takes up the slot and still applies its speed penalty — it just produces nothing extra.
Allowed: Advanced circuit, Automation science pack, Battery, Chemical science pack, Copper cable, Copper plate, Electric engine unit, Electronic circuit, Engine unit, Explosives, Flying robot frame, Iron gear wheel, Iron plate, Iron stick, Logistic science pack, Low density structure, Lubricant, Military science pack, Nuclear fuel, Plastic bar, Processing unit, Production science pack and 9 more.
Not allowed: Accumulator, Active provider chest, Arithmetic combinator, Artillery shell, Artillery turret, Artillery wagon, Assembling machine 1, Assembling machine 2, Assembling machine 3, Atomic bomb, Personal battery, Personal battery MK2 and 137 more. The rule of thumb: if it goes into a machine or your inventory as a finished object, productivity is off the table.
Module effects, straight from the game data
| Module | Speed | Productivity | Energy use | Usable in beacons |
|---|---|---|---|---|
| Efficiency module | 0% | — | -30% | yes (energy) |
| Efficiency module 2 | 0% | — | -40% | yes (energy) |
| Efficiency module 3 | 0% | — | -50% | yes (energy) |
| Productivity module | -5% | +4% | +40% | no |
| Productivity module 2 | -10% | +6% | +60% | no |
| Productivity module 3 | -15% | +10% | +80% | no |
| Speed module | +20% | — | +50% | yes |
| Speed module 2 | +30% | — | +60% | yes |
| Speed module 3 | +50% | — | +70% | yes |
Beacons accept speed and efficiency modules only. Productivity and quality modules cannot be inserted into a beacon at all — that restriction is in the game data, not a player convention.
Same item, 60 per minute: bare machines vs endgame setup
Bare = assembling machine 1 and stone furnaces, no modules. Endgame = assembling machine 3, electric furnaces, 4 productivity module 3 in every machine, 8 beacons with speed module 3. "Ore and coal" adds up every mined raw input in the chain.
| Item (60/min) | Machines, bare | Machines, endgame | Ore+coal, bare | Ore+coal, endgame |
|---|---|---|---|---|
| Iron plate | 3.2 | 0.3 | 60 | 50 |
| Copper plate | 3.2 | 0.3 | 60 | 50 |
| Steel plate | 32 | 2.5 | 300 | 208 |
| Iron gear wheel | 7.4 | 0.4 | 120 | 71 |
| Electronic circuit | 10.5 | 0.5 | 150 | 74 |
| Advanced circuit | 42.4 | 2 | 480 | 190 |
| Processing unit | 315.5 | 11.6 | 3,966 | 1,331 |
| Plastic bar | 0.5 | 0.1 | 30 | 23 |
| Low density structure | 160.5 | 9.5 | 1,950 | 1,094 |
| Engine unit | 67.8 | 3.8 | 540 | 271 |
| Electric furnace | 574 | 38.1 | 6,600 | 4,032 |
| Utility science pack | 464.8 | 15.7 | 5,220 | 1,570 |
Notice that the machine count falls far more than the ore does. Beacons do the heavy lifting on machine count; productivity does the work on the input side. They are not substitutes — you want both, which is exactly why the standard endgame build is productivity in the machine and speed in the beacons.
Run your own numbers in the production chain calculator — it has the same modules and beacons panel, and it walks whatever rate you type.
Common questions
Do beacons stack with modules in the machine?
Yes. Machine modules and beacon effects are added together inside the same speed multiplier. A machine with four productivity module 3 (−60% speed) and eight beacons (+424% speed) still ends up 4.64× faster than bare.
Can I use different modules in different machines?
Yes, and that is how most real bases end up: productivity where the recipe allows it, speed everywhere else. The calculator has a "different setup per machine type" switch that gives assembling machines, furnaces, chemical plants, centrifuges and refineries their own model, modules and beacon count. Changing one of them leaves the others exactly as they were — the machine counts for the other steps do not move unless the demand feeding them changed.
Why does my beacon do nothing?
Three usual causes: the building is a stone furnace, steel furnace or assembling machine 1 and has no module slots; the beacon itself is empty; or the beacon is empty of matching modules while holding productivity modules, which cannot be inserted.
Is it better to fill a beacon with two speed module 3s or one?
Two, always, if speed is what you want — the beacon's effect is the sum of the modules inside it, multiplied by transmission strength. An empty slot is wasted transmission.
How many machines does the endgame setup save?
Depends on the chain length, because the saving compounds at every step. For 60 advanced circuits per minute it goes from 42 machines with tier-1 assemblers and stone furnaces to 2 machines with the endgame setup — and the ore and coal feeding it drops from 480 to 190 per minute. The table above has the per-item numbers.
Numbers on this page are computed at build time from the same recipe and module data the calculator uses, dumped from Factorio 2.0.55. Beacon transmission, module slots and productivity permissions all come from the game prototypes, not from a wiki transcription.