Iron plates: plan the line and find the bottleneck

When this applies

Standard iron-ingot and iron-plate recipes, 100% machine clocks, no production augmentation. One shared belt carries each of the three stages, all at the selected belt capacity. Mining, power generation and alternate recipes are outside the process totals.

Use standard 1× recipe-cost and power-consumption settings. Different game-mode multipliers require a different calculation; these results do not adjust for them.

Before you start

• Write down the target plates per minute, sustained ore supply and belt capacity. A node's potential output is not the same as ore actually arriving at the smelters.
• Count smelters and constructors separately. Keep the ore line, ingot line and plate output visible while checking the factory.

Keep beside the game

The recipe amounts below are per cycle. The rates are for one continuously supplied machine at 100% clock.

For a target T: ore and ingots each need 1.5 × T per minute. Smelters = round up(1.5 × T ÷ 30); constructors = round up(T ÷ 20). Round each process separately, then add the building counts.

At 80 plates per minute, four smelters and four constructors need 120 ore per minute. The eight active process buildings draw at most 32 MW. This does not include the miner or the rest of your factory.

For 81 plates per minute, whole buildings round to five smelters and five constructors. Their full capacity is 100 plates per minute, requiring 150 ore per minute. The target itself requires only 121.5 ore per minute. Feeding less than full capacity can cause intermittent activity; installed capacity is not promised production.

Belt capacity: 60 / 120 / 270 / 480 / 780 / 1,200 per minute

Fix the limiting belt before adding more machines

Plan 81 plates per minute with 5 smelters and 5 constructors. Compare the same buildings while changing only ore supply and shared belt capacity.

Why the result changes

More ore alone leaves the 120-capacity belt limiting output to 80. A 270-capacity belt with 121.5 ore supports 81; supplying 150 ore raises the ceiling to 100. That ceiling is not a promise of sustained output.

Check this in game

After the line fills, inspect ore and ingot delivery separately. If supply and transport are sufficient, check blocked outputs and power before expanding.

Your next steps

1. Build the smelters and constructors from the process counts. The material list covers those buildings only; belts, splitters, miners and power connections need their own materials.
2. Route ore to every smelter, then distribute ingots to every constructor. Check each shared belt and each branch; the total line capacity does not guarantee equal delivery to every machine.
3. Provide power and a clear plate output. Let the line fill before comparing sustained production with the target.
4. If production is short, follow the diagnosis below. Add machinery only when the existing process capacity is the actual limit.

When the result is different

What this does not establish

Parallel belts, changing clocks, alternate recipes and augmented output need a different calculation. The process power shown is maximum active demand, not average electricity use. Use the manual calculator below only when you know the rate of the particular process you are calculating.