Density varies
Fine sugar packs more mass into a volume than rolled oats. Even similar flours vary by milling, protein level and moisture.
Technique adds variation
Dipping a cup directly into flour compresses it differently from spooning and levelling. Recipes written by volume depend on a consistent method.
Choose the original measurement
When a reliable recipe gives grams, keep grams rather than converting to cups. Conversion is most useful when the original uses a different system.
Practical checklist
- Treat conversion values as ingredient-specific.
- Do not use a liquid measuring jug for dry precision.