Factorio Science Guide: Blue Science Wall, Ratios & Lab Counts

Factorio Science Progression — The Blue Wall, the Ratios, and How Many Labs

Last verified: June 12, 2026 against the Factorio 2.0 recipe set. Ratios unchanged in the announced 2.1 plans.

Every Factorio run has the same stall point. Red science: trivial. Green science: a pleasant afternoon. Then blue science arrives and the factory grinds to a halt — a complaint so universal that "the transition to blue is a massive wall" threads still hit the front page of r/factorio in 2026. This page is the reference for getting through it and the stages after: exact recipes, the assembler ratio, lab math, and the order of operations that turns the wall into a ramp.

The recipes that matter (2.0 values)

• Automation (red): 1 copper plate + 1 iron gear wheel → 1 pack (5s). Raw cost ≈ 2 iron + 1 copper per pack.
• Logistic (green): 1 transport belt + 1 inserter → 1 pack (6s). Raw cost ≈ 5.5 iron + 1.5 copper.
• Chemical (blue): 1 sulfur + 3 advanced circuits + 2 engine units → 2 packs (24s). Raw cost per pack ≈ 12 iron + 7.5 copper + 1.5 coal + ~38.5 crude oil.
• Production (purple): 30 rails + 1 electric furnace + 1 productivity module → 3 packs (21s). Raw cost per pack ≈ 52.5 iron + 19 copper + 11.7 stone + 68 oil.
• Utility (yellow): 2 processing units + 1 flying robot frame + 3 low density structures → 3 packs (21s). Raw cost per pack ≈ 33 iron + ~50 copper + 107 oil.

Read the raw-cost column once and the difficulty curve explains itself: blue costs roughly 4x green in iron and introduces oil; purple quadruples it again and introduces stone-at-scale; yellow flips the bottleneck to copper and oil. Each tier is less a recipe and more a new department of the factory.

The same six recipes as the game stores them

The raw-cost figures above are worked out from the ingredient chain. These are the recipe rows themselves, read out of the vanilla 2.0.77 data set with no Space Age mods loaded, because the exact output count and craft time are what the ratio below is built from. Craft time is the recipe's own time at crafting speed 1.0; an assembling machine 1 runs at 0.5, a machine 2 at 0.75 and a machine 3 at 1.25, so divide by your tier's speed to get real seconds.

The assembler ratio: 5 : 6 : 5 : 12 : 7 : 7

The last column of that table is the ratio. Divide each recipe's craft time by how many packs it yields and you get 5, 6, 5, 12, 7, 7 directly, with no rounding and no assumption about which assembler tier you use, because the tier cancels out when every line runs the same one. That is where the famous number comes from, and it is worth knowing you can re-derive it yourself in ten seconds rather than trusting a chart.

The number that matters is the 12. Blue science's 24-second craft for 2 packs is so slow that you need more than twice the assemblers of red science for the same output. Under-building blue assembly is the second most common cause of the wall, right after the advanced-circuit drought covered below.

Two details the ratio hides. The military line looks cheap at 5 but its ingredients are not: 2 stone walls per craft means 10 stone bricks, so 20 stone, per 2 packs. And the purple line's 30 rails per craft is 15 rail crafts, each of which is 1 stone, 1 iron stick and 1 steel plate for 2 rails, which is the real reason purple science turns into a stone and steel project.

One more thing the data set says outright: all six science-pack recipes carry the flag that marks a recipe as productivity-capable. So do advanced circuit, engine unit, low density structure, processing unit, flying robot frame, sulfur, plastic bar, steel plate and both circuit tiers, which is most of the blue and yellow chain. The flag is absent from the rows for rail, electric furnace, productivity module, inserter, transport belt, pipe and lab. Plan your module spend against the flagged recipes rather than assuming it applies everywhere in the chain, and check a recipe in game before you commit a row of beacons to it.

Why the blue wall is really an advanced-circuit wall

When blue science stalls, players stare at the science assemblers. Wrong suspect, almost every time. The real chokepoints, in observed order of frequency:

• Advanced circuits (red circuits). Each needs 2 green circuits + 4 copper cable + 2 plastic, and the copper-cable demand silently doubles your copper consumption. A dedicated red-circuit block with its own cable assemblers — not a corner of the mall — is the single fix that gets most blue lines moving.
• Sulfur and plastic. Both come from oil. If you reached blue without petroleum cracking, your refinery output is mis-balanced within an hour. Basic oil processing → advanced processing + cracking is itself a blue-science-era milestone; plan it first, not last.
• Engine units. Steel + gears + pipes in a 10-second assembler craft. They are not hard, just forgotten — engines are the ingredient most often hand-fed "temporarily" for the first hundred packs.

The order of operations after green science, then: oil first, red circuits second, engines third, science assembly last. Build in that order and the wall mostly fails to materialize.

How many labs?

Labs are the one building with no fixed ratio — the honest answer is a method, not a number:

• Pick a science-per-minute target. 60 SPM is the classic "comfortable mid-game" number; it means producing one of each active pack per second.
• Add labs until packs stop backing up. A lab consumes one set of packs per research cycle, sped up by research-speed technologies; faster research = fewer labs needed for the same pack supply. Early game, 10-20 labs absorbs a yellow belt of mixed packs comfortably.
• Megabase scale is a different sport. 1000+ SPM bases run hundreds of beaconed, moduled labs — at that point lab count is a power-and-beacon question, not a science one.

The lab's own numbers, from the same 2.0.77 vanilla data: researching speed 1.0, two module slots, 60 kW while it is working, 150 hit points, and it costs 10 electronic circuits, 10 iron gear wheels and 4 transport belts to build in a 2 second craft. The 60 kW is the figure worth carrying around, because lab power is the cost people forget to budget: a hundred labs is 6 MW of draw before a single beacon, and a beacon is another 480 kW each on top of that.

What the whole tree actually costs

Here is a number almost nobody has, and it falls straight out of the technology table. Adding up every vanilla 2.0.77 technology that has a fixed research cost gives the total science pack bill for finishing the tree:

Two caveats and then the useful part. Nine of the 196 vanilla technologies are the infinite ones whose cost is a formula rather than a number (mining productivity, the damage and robot lines, artillery range and speed), so they are excluded. Seven more carry no science cost at all in the data set: automation science pack, electronics, oil processing, space science pack, steam power, steel axe and uranium processing. Those seven are the ones the game hands you for doing something rather than for spending packs, which is why the early tree feels like it has gaps in it.

The useful part is the time. Those 180 technologies add up to 2,078,075 lab-seconds at researching speed 1.0, which is 577 hours in a single unmodded lab. Twenty labs takes that to about 29 hours of continuous research, and that is before any research speed technology, module or beacon. It is also why the 60 SPM target is the sane one: at 60 packs per minute of each active type you are spending roughly an hour of real time per 3,600 packs, and the red and green columns alone are 99,635 packs.

The wall after yellow

The most expensive research in vanilla is not the rocket silo. It is atomic bomb, at 5,000 units of 45 seconds each with one of all six packs per unit, which is 225,000 lab-seconds, or 62 hours in a single lab, more than a tenth of the whole tree in one technology. Spidertron is second at 2,500 units of 30 seconds. Rocket silo is joint third at 1,000 units of 60 seconds with five pack types, tied with mining productivity 3, and it needs eight prerequisite technologies of its own. Then you have to build the thing, and its recipe is 1,000 steel plates, 1,000 concrete, 200 processing units, 200 electric engine units and 100 pipes in a 30 second craft. Each rocket part after that is 10 processing units, 10 low density structures and 10 rocket fuel. If blue science is a supply-chain exam, the silo is the final: it is the first recipe in the game where a four-digit ingredient count is normal, and a base that cleared the purple ramp properly usually walks into it while a base that hand-fed its way through blue does not.

Multiplayer notes

On a server, the science stages map neatly onto a division of labor: one player owns oil and chemicals, one owns circuits, one owns rails and smelting for the purple ramp. The blue wall that stalls a solo run for an evening dissolves in an hour with three players who each take one ingredient chain. If your group is heading to Space Age afterwards, the same discipline — one production chain, one owner — is exactly what Gleba punishes you for not having. For server sizing as your SPM target grows, see hardware requirements.

Building toward a group megabase? Host a Factorio server with Supercraft — UPS headroom for the purple-science rail ramp and beyond.

Looking for managed Factorio server hosting? Supercraft runs Factorio dedicated servers with daily backups, instant setup, and 4 region options.