Check which flour the recipe means
All-purpose, bread, whole-wheat, almond and coconut flour are separate entries in the ingredient directory. Choose the entry that actually appears in your recipe. A similar name does not make two ingredients interchangeable.
The converter changes a quantity, not the composition of a recipe. If you plan to replace one flour with another, use a suitable substitution instruction from the recipe author instead of relying on a cup conversion.
Weigh the published amount first
When a recipe lists grams, put your bowl on a scale, zero it and add the listed mass. This is the most direct way to follow that measurement. It also avoids guessing how closely your filled cup resembles the reference cup.
Our default all-purpose flour entry uses a published 120-gram-per-cup reference. That is the selected recipe reference, not a claim that every cup filled with every flour product will weigh exactly that much.
If you are measuring with a cup
Follow the recipe’s stated measuring technique. King Arthur’s guidance describes lightly filling the cup and levelling the top, rather than compressing the flour. A scale remains useful for checking your own result.
Use an actual measuring cup and read its unit marking. Do not change to a metric cup halfway through a recipe that was written with US measures unless you recalculate the quantities consistently.
Use conversions with context
For the default all-purpose flour entry, 50 grams divided by 120 grams per adopted US cup gives approximately 0.42 cups. That decimal is a reference estimate. A convenient rounded fraction should not replace it silently.
When two charts disagree, compare the flour type, preparation notes, cup system and source before choosing a number. For a specific recipe, the author’s stated gram quantity has priority over a general chart. Save that decision with the recipe so your next batch uses the same convention.