Satisfactory load balancer & belt calculator

Your production planner tells you how many machines. This tells you how to wire them: enter what one stage produces and what the next one consumes, and it packs the machines into belt lines and shows how to connect them, direct, merged or through a balancer, with the exact piece count.

How it works

Between two stages of a factory there are three belt segments. The tool solves each one and shows the result above.

Collection

Joins the source machines into belt lines with mergers (an output manifold). Machines per line = belt capacity ÷ rate per machine, rounded down. Leftover machines share a partial line.

Middle

Connects the collection lines to the distribution lines. This is where lines get merged, topped up by a donor line or split by a load balancer.

Distribution

Splits each incoming line among the destination machines with splitters (an input manifold). A manifold balances itself across machines, so the tool only balances between lines.

The cases in the middle

• Case A Source line ≥ destination line. One source line straight into each destination. The excess backs up at the source and spare lines follow your policy.
• Case B Source line a bit short. A donor line is split into equal parts, one per destination, and each part is merged into a main line.
• Case C Source lines much smaller than destination lines. Several whole source lines are merged into one, within the belt capacity and 3 inputs per merger.
• Case D Mixed lines. A line with surplus sends its excess, through a Smart Splitter’s Overflow output, to a destination that is short. If no simple layout exists, the tool says so.

Game rules it follows

• Splitter Up to 3 outputs, divides evenly among the outputs that accept items. Direct splits only reach halves and thirds (1/2, 1/3, 1/4, 1/6, 1/9…).
• Merger Up to 3 inputs, takes from them in turn. A top-up line running in series through several mergers is drained by the first ones, so the tool never suggests that.
• Smart Splitter The Overflow output only gets items when the Any output is full. That lets a line fill its own destination first and pass on only the excess.
• Awesome Sink Takes any leftover. Backing up at the source is fine too: the machines there just slow down.

Load balancer library

Build an N→M balancer from scratch: pick how many belts go in and how many come out, and the tool tries every design, checks the rate on each segment and shows the build piece by piece.

What it is

A load balancer is a set of splitters and mergers that takes N belts and delivers M belts at exactly the same rate, no matter how much each input carries. There is no “balancer” piece in the game: you build it from regular pieces.

How it works

A splitter divides evenly among the outputs that accept items, into 2 or 3. Chaining splitters cuts a belt into any product of 2 and 3 (2, 3, 4, 6, 8, 9, 12…). A merger joins up to 3 belts, taking from each in turn. A matrix uses both: each input is cut into M equal parts and each output gets one part from every input, so every output adds up to the same.

Why use one

A manifold balances itself across machines, but not across lines: if one destination line gets 455 and another 300, the machines on the second starve forever. A balancer makes every line carry the same share of the total. It’s also how you split a belt into 5 or 7, which a splitter can’t do directly.

When you don’t need one

If each source line already covers a destination, connect them directly. If the shortfall is small, a split donor line or a Smart Splitter with overflow does it with fewer pieces. The alternatives above compare this for your case.

Butterfly and vertical builds

Instead of every input reaching every output, a butterfly mixes belts in pairs, over rounds: first 1 with 2 and 3 with 4, then one result from each pair. Since it’s the same block repeated, you can stack one round on top of the other and join the floors with lifts, which is the compact vertical balancer people build. With a count not made of 2s and 3s (5, 7) or with inputs ≠ outputs, it uses empty lanes or spare lanes that loop back.

How to build your own

1. Write M as a product of 2 and 3, the 2s first (6 = 2 × 3: 3 splitters, while 3 × 2 takes 4). If you can’t (5, 7, 10…), use the next number that works and choose: loop or sink.
2. On each input, build the tree: one splitter for the first factor, then one splitter on each output for the next factor.
3. For each output, take the part with the same number from every input and join them with a merger. With more than 3 inputs, chain mergers.
4. Loop: the extra parts go back to a merger before the first splitter (3 or more parts: cascaded mergers). Sink: they go to the Awesome Sink.
5. Check the belt on every segment. If the total fits on one belt, the funnel (merge everything, then split) uses far fewer pieces.

Ready-made balancers

• 1 → 3
• 1 → 4
• 1 → 5
• 1 → 6
• 1 → 7
• 1 → 8
• 1 → 9
• 1 → 10
• 2 → 3
• 2 → 4
• 2 → 5
• 2 → 6
• 2 → 7
• 3 → 2
• 3 → 4
• 3 → 5
• 4 → 2
• 4 → 3
• 4 → 5
• 4 → 6
• 5 → 4
• 5 → 6
• 6 → 4
• 6 → 5
• 6 → 8
• 8 → 6
• 2 → 2
• 3 → 3
• 4 → 4
• 5 → 5
• 6 → 6
• 7 → 7
• 8 → 8
• 9 → 9
• 12 → 12

Questions

Why can’t a splitter make 5 equal parts?

A splitter divides by 2 or 3, so chaining them only reaches products of 2 and 3. For 5 parts you either build a balancer with a loop (some outputs go back to the input) or split into 6 and send the sixth part to the sink. The tool shows both.

Where do the numbers come from?

From you. The tool knows no recipes: type the machine count and the per-minute rate from your production planner or from the recipe in the game.

Is my plan saved?

Yes, only in your browser, and you can save several named scenarios. There’s no account and nothing you type is sent to a server. The Copy link address carries the scenario in the address itself, after the #, a part the browser doesn’t send to the server.

Which game version?

Satisfactory 1.0 and later, with belts from Mk1 (60/min) to Mk6 (1,200/min).

Can I use a mod or a ready-made blueprint instead?

Yes. If you play with mods, Modular Load Balancers (unlocked at Tier 4) adds modules that snap together into a group and split items equally among all its outputs, any size. If you play vanilla, Satisfactory Calculator has balancer blueprints shared by other players. Either way the tool still answers what comes before: how many lines, whether you need a balancer and which N→M.

Does it work with fluids?

Yes. Pick "Fluid (pipe)" and the pipe tier (Mk1 300, Mk2 600 m³/min). Since pipes have no splitter, the tool doesn’t build a balancer: it groups the machines per pipe and joins or divides the pipes with Pipeline Junctions, within capacity. Height and pumps are up to you.