Factorio ratios — how many machines per belt
The question behind most Factorio ratio searches is one number: if I run a full belt of ore into a row of furnaces, how many furnaces do I need? This page answers that for every craftable item in the base game, not just iron and copper — including the ratios nobody bothers to tabulate because they are awkward.
Machines needed for one full belt
A full yellow belt moves 900 items per minute, red 1,800, blue 2,700. Pick your assembling machine tier — furnaces, chemical plants and centrifuges are unaffected.
Most-used ratios
The ones people actually look up — smelting, circuits, and the science packs.
| Item | Machine | Yellow (900/min) | Red (1,800/min) | Blue (2,700/min) |
|---|---|---|---|---|
| Iron plate | Furnace | 48 | 96 | 144 |
| Copper plate | Furnace | 48 | 96 | 144 |
| Steel plate | Furnace | 240 | 480 | 720 |
| Electronic circuit | Assembling machine | 15 | 30 | 45 |
| Advanced circuit | Assembling machine | 180 | 360 | 540 |
| Processing unit | Assembling machine | 300 | 600 | 900 |
| Copper cable | Assembling machine | 7.5 | 15 | 22.5 |
| Iron gear wheel | Assembling machine | 15 | 30 | 45 |
| Plastic bar | Chemical plant | 7.5 | 15 | 22.5 |
| Automation science pack | Assembling machine | 150 | 300 | 450 |
| Logistic science pack | Assembling machine | 180 | 360 | 540 |
| Chemical science pack | Assembling machine | 360 | 720 | 1,080 |
| Production science pack | Assembling machine | 210 | 420 | 630 |
| Utility science pack | Assembling machine | 210 | 420 | 630 |
All Assembling machine recipes (166)
All Furnace recipes (4)
| Item | Yellow (900/min) | Red (1,800/min) | Blue (2,700/min) |
|---|---|---|---|
| Copper plate | 48 | 96 | 144 |
| Iron plate | 48 | 96 | 144 |
| Steel plate | 240 | 480 | 720 |
| Stone brick | 48 | 96 | 144 |
All Chemical plant recipes (8)
| Item | Yellow (900/min) | Red (1,800/min) | Blue (2,700/min) |
|---|---|---|---|
| Battery | 60 | 120 | 180 |
| Explosives | 30 | 60 | 90 |
| Flamethrower ammo | 90 | 180 | 270 |
| Lubricant | 1.5 | 3 | 4.5 |
| Plastic bar | 7.5 | 15 | 22.5 |
| Solid fuel | 15 | 30 | 45 |
| Sulfur | 7.5 | 15 | 22.5 |
| Sulfuric acid | 0.3 | 0.6 | 0.9 |
All Centrifuge recipes (2)
| Item | Yellow (900/min) | Red (1,800/min) | Blue (2,700/min) |
|---|---|---|---|
| Nuclear fuel | 1,350 | 2,700 | 4,050 |
| Uranium-238 | 300 | 600 | 900 |
How to read the table
Each row answers: how many machines does it take to produce one full belt of this item per minute. A yellow belt carries 15 items per second (900/min), red 30 (1,800/min), blue 45 (2,700/min) in Factorio 2.0.
The number is calculated from three things: the recipe's craft time, how many items one craft produces, and the machine's crafting speed. Rows are sorted by machine count within each machine type, so the most expensive steps in the game are at the top of each table.
These are bare machines with no modules and no beacons. Speed modules cut the machine count by roughly the module percentage, and productivity modules cut it too — a machine with productivity produces more items per craft, so you need fewer machines for the same output, as well as less input. Both are covered on the modules and beacons page.
Common Factorio ratios
How many furnaces for a full belt of iron or copper plate?
48 stone furnaces, or 24 steel/electric furnaces. A stone furnace smelts one plate every 3.2 seconds — 18.75 per minute — and 900 ÷ 18.75 = 48. Steel and electric furnaces run at speed 2, so exactly half. Double both numbers for a red belt, triple for blue.
How many furnaces for a full belt of steel?
240 stone furnaces, or 120 steel/electric furnaces. This is the ratio everyone gets wrong, and it is five times the iron number because steel takes 16 seconds instead of 3.2. If you are trying to fill a belt with steel using stone furnaces, you need more furnaces than most bases ever build — which is why steel belongs on its own dedicated line, fed from an iron plate belt, not bolted onto your iron smelting.
How many assembling machines for a full belt of green circuits?
15 at assembling machine 1, 10 at tier 2, 6 at tier 3. One electronic circuit takes 0.5 seconds, so a tier-1 machine (speed 0.5) makes 60 per minute, and 900 ÷ 60 = 15.
Why are some numbers in the hundreds?
Advanced circuits need 180 tier-1 assembling machines per yellow belt, and processing units need 300. That is not a mistake — a processing unit takes 10 seconds and produces one item, so a tier-1 machine makes 3 per minute. A full blue belt of processing units would need 900 machines, which is why nobody builds one.
When these ratios do not apply
Three things break a static ratio, and all three are common by mid-game:
- Modules and beacons. Speed modules and beacons change machine counts directly — an electric furnace with two productivity module 3 and eight speed beacons runs at 4.94× speed, so a beaconed furnace array needs about a fifth of the machines.
- Productivity. Productivity modules raise output per craft, so they cut both the machine count and the input demand — the whole upstream chain shrinks. See modules and beacons for the per-item numbers.
- Belt throughput in practice. A "full belt" is a theoretical 900/min. Real belts lose a few percent to inserter swings, side-loading and lane imbalance. If you are sizing a build for exactly one belt, add 5–10%.
When modules are in play, use the production chain calculator instead — it walks the whole tree for whatever rate you enter, and shows the raw materials behind it.