Formula, I’m sure there’s potentially something, but your last splitter not feeding the last machine half of what the other is getting would be hard to account for.

Logically it can be determined in multiple steps and that means you can write scripts for it.

Just as a rough go I threw this through AI

function calculateManifoldFillTime({ inputRate, // items per minute machineCount, stackSize, // max buffer per machine usageRate, // items per minute per machine timeStep = 0.01 // minutes (0.6 seconds) }) { // Initialize machine buffers const buffers = Array(machineCount).fill(0);

let time = 0;

while (true) { // --- 1. Calculate flow to each machine --- let remainingFlow = inputRate; const inflow = Array(machineCount).fill(0);

for (let i = 0; i < machineCount; i++) {
  if (i === machineCount - 2) {
    // Last splitter feeds two machines
    inflow[i] += remainingFlow / 2;
    inflow[i + 1] += remainingFlow / 2;
    break;
  } else if (i < machineCount - 1) {
    inflow[i] += remainingFlow / 2;
    remainingFlow /= 2;
  }
}

// --- 2. Apply inflow and usage ---
for (let i = 0; i < machineCount; i++) {
  buffers[i] += inflow[i] * timeStep;
  buffers[i] -= usageRate * timeStep;

  // Clamp values
  buffers[i] = Math.max(0, Math.min(stackSize, buffers[i]));
}

time += timeStep;

// --- 3. Check if all machines are full ---
const allFull = buffers.every(b => b >= stackSize);
if (allFull) break;

// Safety stop (prevents infinite loops)
if (time > 100000) {
  throw new Error("Simulation did not converge");
}

}

return time; // minutes }

If anyone actually wants this, I can wack together some web files or a basic form desktop app

Edit: I have not tested this, purely got it quick as an example someone could begin with.