Convert a decimal comma without changing the quantity on a label
Preserve the original numeric text while converting a confirmed decimal convention into calculator-ready numbers.
A food label may print a quantity with a comma where your calculator expects a decimal point. Preserve the original text first, then convert the number using the convention confirmed for that panel. Removing punctuation blindly can turn a small quantity into a much larger one.
Keep a raw-text column
Copy the amount exactly as printed, including its separator and unit. Create a second column for the numeric value used in calculations. Label the conversion assumption in the note, such as comma interpreted as decimal separator after checking the full panel.
For a fictional example, the source reads 1,5 g for the chosen nutrient per 100 g of food. With the decimal convention confirmed, enter 1.5 g into a calculator expecting a point. Do not convert it to 15 g by stripping the comma.
Check the whole panel, not one isolated mark
Inspect neighboring values, the panel language and any matching manufacturer presentation. A comma-shaped print defect or a cropped separator should remain unresolved until readable. Do not assume every comma in an exported spreadsheet has the same role; delimiters between columns are different from punctuation inside a number.
The European Commission nutrition-labelling guide explains the per-100-g or per-100-ml declaration basis. Keep that basis attached during conversion: changing numeric notation does not change the amount of food to which the value refers.
Test the conversion with one portion
For the invented 1.5 g per 100 g value, a 40 g portion gives 1.5 × 40 ÷ 100 = 0.6 g. If the comma had been deleted, 15 × 40 ÷ 100 would give 6 g. The example illustrates a tenfold transcription difference; it does not tell you which interpretation is correct without reading the source.
When moving the record between spreadsheets, inspect the imported cell type. A value may arrive as text, a decimal or several separate fields depending on the import settings. Verify a sample row before trusting a whole column of calculated results.
Save both the raw text and the parsed value in your final record. If another person uses a different language setting, they can see exactly what was printed and how you interpreted it. For ambiguous punctuation, leave the parsed field empty and state what additional evidence is needed.