Sizu Riatto
Book 3 · Kitchen Math

Nutrition Label Calculator

Type in the label, then type in what you actually ate. You get the corrected numbers, the macro split by the 4-4-9 rule, a cross-check against the printed calories, and the per-100 g figure that makes two products comparable.

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What the label says — per serving

What you actually ate

Fill in the label and press Calculate.

Compare two products fairly — per 100 g

Manufacturers pick their own serving sizes, so "calories per serving" is not a fair comparison. Per 100 g is.

Enter both products and press Compare.
From the book — Chapter 4. Protein and carbohydrate carry 4 calories per gram; fat carries 9. So the printed calorie figure should be close to (protein × 4) + (carbs × 4) + (fat × 9) — a gap of a few calories is just label rounding, but a large one is worth a second look. To correct for what you really ate, divide the amount eaten by the serving size and multiply every label number by that. And to compare two products, put both on a per-100 g footing: (label value ÷ serving grams) × 100.

% DV figures are based on a 2,000-calorie reference diet and are a guide, not a prescription. Educational only — not dietary or medical advice. Everything stays in your browser.