To start Factorio well, these beginner ratios stop empty belts, short smelting lines and collapsing steam power. This guide stays on the base game without Space Age. Its goal is a stable factory through blue science. The numbers below were checked against the official electric mining drill page, the official power production page and the official science pack documentation. For more reading, you can also open this main bus guide, this train signals article and our other PC guides.
Key points
- A yellow belt carries 15 items per second.
- An electric mining drill outputs 0.5 resource per second.
- 30 drills fill one yellow belt of ore.
- 24 steel or electric furnaces fill one yellow belt of plates.
- The official steam ratio is 1 boiler for 2 steam engines.
Factorio beginner ratios: the 7 numbers to learn first
The hardest part early on is not space. It is the lack of benchmarks. With a few numbers in mind, you can tell whether the real problem is ore, plates or power.
| Block | Useful value | Simple decision |
|---|---|---|
| Yellow belt | 15 items per second | Baseline for your first factory math. |
| Electric mining drill | 0.5 resource per second | Plan around 30 drills for one full yellow belt. |
| Stone furnace | 48 machines per yellow belt | Short-term answer before a proper steel setup. |
| Steel or electric furnace | 24 machines per yellow belt | Clean format for the main smelting line. |
| Boiler and steam engine | 1 to 2 | Safe reference for scaling early power. |
| Practical steam block | 1 pump, 20 boilers, 40 engines | Fast copy before a major expansion. |
| Base-game science | 5:6:5:12:7:7 | Useful target once the factory is stable. |
Read the factory in this order. If ore is missing, count miners. If ore arrives but plate belts have gaps, count furnaces. If everything slows at once, check steam power before placing more assemblers.
Clear steps to build a stable first line
You do not need a mega factory. You need a readable line first. Follow these steps in order.
- Place iron and copper miners with one open side for later expansion.
- Split coal early so smelting does not collapse when demand rises.
- Start with simple smelting, then keep room for a later 24-furnace steel line.
- Keep iron, copper and steel on separate lanes.
- Add green circuits only after your steam block is stable.
- Move to 4 to 6 labs once science packs arrive without gaps.
The main bus is not mandatory. It is still the easiest way to avoid spaghetti in a first run. Iron, copper, steel and green circuits travel well. Copper cable is usually better made on site.
Factorio beginner ratios: when to scale steam and science
Power failure is often the most deceptive early issue. Inserters slow down. Miners blink. Labs stall. In many factories, the layout is not the real problem. The steam block was simply expanded too late.
The official reference is simple. Keep 1 boiler for 2 steam engines. At full scale, one offshore pump supports 200 boilers and 400 steam engines. In early play, the most practical chunk is 1 pump, 20 boilers and 40 steam engines.
- Add a steam block before a major smelting expansion.
- Prepare another block when electric mining ramps up.
- Check power before military or chemical science.
- If machines blink yellow, stop adding assemblers.
For research, start with 2 red science assemblers, 2 green science assemblers and 4 to 6 labs. That is enough to move the base forward. Once smelting and steam are stable, you can aim for the official 5:6:5:12:7:7 science ratio for clean base-game progression.
Mistakes to avoid before blue science
- Placing assemblers before leaving room to double smelting.
- Putting copper cable on the main bus.
- Adding labs when science packs already fail to reach the first one.
- Upgrading to red belts before finding the real bottleneck.
- Trying to defend the whole map with too little ammo instead of locking key entrances.
- Forgetting that the first automatic turret uses magazines, not electricity.
Key takeaway
If you are unsure what to fix next, use this order: power, plates, green circuits, science, then defense. In most early factories, the visible problem appears after the real shortage. Good ratios help you trace that chain faster.
For more reading, you can also check our guide to a clean bus, our train signal article and the latest updates on the site.
Frequently Asked Questions
How many electric miners fill one yellow belt?You need 30 electric mining drills. That is the easiest benchmark for an early iron or copper line.
You need 24 steel furnaces. If you are still using stone furnaces, the same throughput needs 48 machines.
The most practical block is 1 offshore pump, 20 boilers and 40 steam engines. It keeps the official ratio in a fast repeatable layout.
Add them when red and green packs arrive without gaps. Before that, spend resources on smelting and power first.
Do it when the yellow belt is already compressed and upstream production can support more throughput. Red belts do not fix missing ore or weak smelting.
Not always. A small local steel block near iron is often cleaner at first. Add steel to the bus once production becomes steady.
The common trap is adding more assemblers and more labs before doubling smelting and steam power. Blue science exposes that shortage very quickly.
The best reference is the official wiki. For general information and official media, keep the official site and the Screenshots page bookmarked.
Verified sources
These links let readers and search assistants verify the main facts used in this article.
- wiki.factorio.com : Checked on 2026-06-12. The official electric mining drill page confirms the 0.5 resource per second rate, the 5x5 mining area and the 90 kW power use.
- wiki.factorio.com : Checked on 2026-06-12. The official Science pack page confirms the 5:6:5:12:7:7 assembler ratio for synchronized base-game science.
- wiki.factorio.com : Checked on 2026-06-12. The official Power production page confirms 1 boiler for 2 steam engines and the 1:200:400 ratio with one offshore pump.
- wiki.factorio.com : Checked on 2026-06-12. The official belt physics page confirms 15 items per second for a yellow belt, 30 for a red belt and 45 for a blue belt.
- wiki.factorio.com : Checked on 2026-06-12. The official Gun turret page confirms that it is the first automatic defense and that it uses magazines rather than electricity.
