There are several different types of calculators available with trade offs for speed and calculating splitter/merger preference.
The calculator can be changed in Settings -> General.
This is the default calculator.
This takes into account the fact that splitters and mergers prefer to split/merge as evenly as possible. It also takes into account priority splitters and mergers.
The values entered in this mode are limits.
This mode most accurately models what happens in Satisfactory.
This can be quite slow on larger builds. Tips to help the full calculator run faster can be found here.
This does NOT take into account splitter or merger preference to split/merge evenly, nor does it take into account priority splitters or mergers.
The values entered in this mode are limits.
This tries to find any solution that maximizes the values and may not always give the same answer if there could be multiple solutions because not enough information was given.
This should always be fast.
This does NOT take into account splitter or merger preference to split/merge evenly, nor does it take into account priority splitters or mergers.
The values entered in this mode are NOT limits, but rather the final values that you want to see.
This mode is most like using a spreadsheet.
If you do not enter enough information, some things can not calculate a value. If you enter too much conflicting information such that they cannot all be true, some with be arbitrarily ignored.
This should always be fast.
This does no calculations at all and leaves the values blank.
You can add numbers in yourself for personal notes but they are not used in any calculations.