In Factorio, you build machines to harvest raw resources like iron ore or crude oil. Those resources are carried by conveyor belt or pipes to other machines that refine the raw materials into production-ready materials like iron plates and petrol. Those are then carried to other machines that turn them into machine parts. Those parts are then carried elsewhere and turned into a final product.

And then things get strange.

You might use that product directly. If the product is something like a conveyor belt or a robotic arm, then maybe you’ll carry that crap around in your inventory and use them to build more stuff. But the other thing that products are used for – and indeed the fate of the vast majority of manufactured products – is to be turned into science bottles.

Science bottles are yet another product. They look like little glass bottles of liquid of varying color. You have your conveyor system deliver them to science labs, and then the bottle is magically turned into research. The bottle vanishes from the world and you gain a little bit of progress towards your next research goal. Once your labs consume enough science bottles, you’ll unlock a new technology.

The early science bottles are fairly simple and can be constructed in just a couple of steps, while the late-game bottles require complex factories and vast quantities of resources.

This idea of turning raw ore into a bottle of colored juice and then turning the juice into knowledge is pretty silly and it’s obviously something you’re not supposed to think about. But we’re going to do it anyway.



What’s in the Bottle?

The buildings on the right pull in iron, and output gears and pipes. The conveyor carries that stuff over to the row of machines in the middle, which makes engines out of them.

Factories never produce solid waste. They take in raw materials and spit out parts, and as far as we can tell nothing is lost in the process. It’s clear we’re not supposed to take this 100% literally, but… what if we did? How much stuff goes into a bottle of science juice? How much would one weigh?

Let’s start with the most basic bottle.

The red science bottle is made from a copper plate and an iron gear. In turn, one iron gear is made from two iron plates. So the raw materials required to make red science is 2 iron plates and 1 copper.

So how big are these metal plates?

Sadly, the game doesn’t give us any indication. The units page of the Wiki doesn’t really give us anything to go on. So we’re going to have to start approximating as best we can.

If we look at them on conveyor belts they look to be about half a meter square and perhaps a few centimeters thick. According to Wolfram Alpha, a block of iron 50cm × 50cm × 5cm would weigh 98kg, or 216 lbs.

I don’t really like this approximation, because it’s clear we shouldn’t be taking the sizes of things on conveyor belts literally either. Everything on a conveyor belt is the same size, regardless of how large or small it might be. A locomotive, a hand grenade, an oil refinery, and a circuit board all take up exactly the same space on the conveyor, so it’s pretty obvious these are more icons than physical representations of the objects.

Likewise, we can’t really use the player’s inventory as a guide. An assembly machine is roughly the size of a compact car, but they can be carried in stacks of 50 and the player’s starting inventory can hold 60 stacks. Moreover, their inventory can mysteriously expand with research and armor upgrades. So we have to regard the player’s inventory as a magical pocket dimension. It’s not something we can use as a guide for determining the scale or mass of an object.

Perhaps we could use the chests in the game? But then we come back to the questions of scale when we ask “How big are the chests?”



I love trains. They're not really useful in the resource-rich maps I prefer, but I build them anyway because they're so cool.

However, there is one container that has properties we should be able to figure out based on appearance: A train. The trains in the game look a lot like real-world trains, and I think it’s not out of line to suggest using real-world trains as a guide for what they can carry. We can then work backwards from this to work out the sizes of the stuff we care about. We still need to do some hand-waving in terms of scale, but I think this is the best we can do.

Consulting various forums for train nerds, it looks like weight capacity can vary quite a bit. But it seems like 100,000lbs (50 tons) is a nice conservative estimate for the payload capacity of a freight car. Let’s assume a fully loaded car in Factorio is carrying that much weight.

A car has 40 inventory slots, and each slot can hold a stack of 100 plates. That’s 4,000 total plates. This means each plate weighs 25lbsAbout 11Kg.. So, picture a good-sized dumbbell.

This means a red science bottle has 25lbs of copper and 50lbs of iron. Total payload: 75 lbs.

The recipe for a green science bottle, which has the boring name "science pack 2".

Next up is the green science bottle, which takes a robot armCalled an inserter, because it inserts things into machines. and one segment of the basic conveyor belt. Somehow those two devices are transformed into a glass bottle of green science juice.

So green science contains 37.5lbs of copper and 125lbs of iron. Total payload: 162.5 lbs.

Now things are going to get crazy. A blue science bottle contains a red circuit board, an “engine”, and an electric mining drill.

The problem we’re running into now is that red circuit boards take two units of plastic, and I have no idea how we’re supposed to work out how much mass is in a hunk of plastic. In the previous case we could argue that 100% of the raw materials was being used because there’s no waste. An iron gear must contain the same iron as two plates, or else every gear-making machine would quickly become buried under a mountain of metal shavings. But an oil refinery consumes crude oil and water and spits out petroleum. A chemical plant mixes the petroleum with coal to form plastic. We can’t argue that all of those raw materials wind up in the plastic bar, since the game clearly shows that some of it is burned off and released to the atmosphere in the form of grey smoke. There’s even gameplay consequences for doing this, so we can’t just hand-wave it all away as cosmetic.

We could use the same trick we used with freight trains to work out the weight, but it turns out that the stack size is the same for both metal plates and plastic. So going by weight would force us to conclude that plastic bars and metal plates have the same weight, and therefore it takes 50lbs of plastic to make a single circuit board.



The recipe for a blue science bottle

I’ve always imagined the circuit board in this game to be the size of a motherboard.

But rather than come to that conclusion, let’s try to make this work. Since we’re free to say that plastic bars are any size we wish (since an unknown quantity of the the raw materials are burned off during production) and since we know it takes two of them to make a circuit board, let’s just make assumptions that make sense. We can argue that plastic bars are one pound apiece. If we need a justification for why a train car can only carry 4,000 of them, we can say they’re light but bulky, and thus you can’t fit more on the train even if the train can easily handle the weight.

Now we just have to work out the rest of the inputs. Blue science takes 25 iron plates, 9.5 copper plates, 2 plastic bars, and an engine. If you run up the production chain a bit you can see an engine is another 9 iron plates.

So blue science contains 850 lbs of iron, 238 lbs of copper, and 2 pounds of plastic. Total payload: 1,090 lbs.



The recipe for a purple science bottle

I always have the worst time getting the bricks into my production line. I think it’s because you introduce bricks late in development and I always forget to leave space for the conveyors.

Purple science takes an assembling machine, an electric furnace, and an electric engine. Now we have a new ingredient to deal with: Stone bricks, which are apparently an important ingredient of the electric furnace. No big deal. They’re bricks. Let’s just assume they’re basically normal bricks. A brick is about 8lbs.

An electric engine is just a regular engine with some circuit boards and lubricant. We can ignore the lubricant since it’s probably negligible in terms of the weight of the engine itself, and you could even argue it’s consumed producing the engine rather than running it. (Since you never add more later to keep the engine going.)

So purple science contains 825lbs of iron, 812lbs of copper, 10lbs of plastic, and 80lbs of bricks. Total payload: 1,727 lbs. Almost a ton!

There’s another bottle of grey science juice that’s used for military stuff, but it’s not very interesting. Not a lot of raw materials go into it and the ingredients are things like bullet magazines and hand grenades, which are of familiar weights. So let’s skip grey science and look at the final bottle.

The recipe for a yellow science bottle

Yellow science juice takes a battery, 3 purple circuit boards, a speed module (whatever that is) 30 units of copper cable, and a battery. Unlike the other items in this list, yellow science bottles consume more copper than iron.

The battery looks like your typical D-Cell battery, but it takes an iron plate and a copper plate. If we stick by my rule that we’re supposedly using ALL the raw materials, then the casing for this battery is 50lbs of metal. Inside of that is 20 “units” of acid, and we don’t have a good way to determine how much that might be.

So the battery is made out of 50 lbs of metal, which would suggest it’s enormous. But the icon says it’s very small. And it’s used by your flying robots, which wouldn’t really work if the batteries were really big. Let’s split the difference and say the batteries are like lightweight car batteries.

So yellow science contains 2,200 lbs of iron, 4,225 lbs of copper, 10 lbs of plastic, and 4 lbs of acid. Total payload: 6,439 lbs.

Adding it All Up

Conveyor belts carry all the different SCIENCE(!) bottles to the dome-shaped labs, where they are consumed.

Like I said earlier, these bottles are consumed by science labs. I don’t know if there’s a black hole in the center of a science lab, or what the deal is. They just vanish.

Adding up all of the bottles we’ve looked atRemember I’m ignoring grey bottles. their total combined weight comes to 9,493.5 lbs, or just short of 5 tons.

One late-game technology is the logistic network, which lets you set up a system to have flying robots move material around your base according to rules you set up. It lets you move things without needing to run conveyor belts, which is good because this late in the game your base is already blanketed in conveyors and it’s really hard to add more. Logics robots aren’t useful for bulk deliveries (they could never deliver copper and iron plates fast enough to be useful) they’re really useful for transporting rare or exotic things near the end of the supply chain.

To unlock this technology you need 150 of each kind of bottle. This means you’re going to feed 1,424,025 lbs (645,928kg) of stuff into the science labs. That’s about 1.7 times the maximum takeoff mass of a Boeing 747. Even if you don’t buy the idea that that much mass ends up in the bottle, your base still consumes that much, one way or another. Either it ends up in the bottle or it ends up as a waste product never depicted in the game.