Nutritional Label Calculator

Fiber isn't fully metabolized the way digestible carbohydrate is, so the Atwater system assigns it a lower energy value. This calculator subtracts fiber grams from total carbohydrate before applying the 4 kcal/g rate to the remainder, then adds fiber back in separately at 2 kcal/g. This two-step split is why total calories aren't simply carbohydrate plus fiber times 4, and it matters most for high-fiber products where lumping fiber in at the full rate would overstate calories.

The calculator expects total carbohydrate to already include fiber, matching how an FDA nutrition label lists it — fiber is a subset of total carb, not a separate deduction you make beforehand — and it performs the fiber subtraction internally when computing net carb calories. Subtracting fiber out yourself before entering total carbohydrate would double-count the deduction and understate total calories.

Each %DV divides your entered grams by the FDA's fixed reference amount for a 2,000-calorie diet — 78 g for fat, 275 g for total carbohydrate, 28 g for fiber, and 50 g for protein — the same reference values printed on a real nutrition facts panel. These %DV numbers don't scale with the calorie content of your specific product; they're a fixed yardstick meant to show how one serving fits into a standard daily intake, not a comparison to your own total calories.

Calorie density divides total calories by the serving size in grams, giving kcal per gram independent of how large a serving is, and the calculator flags roughly under 1.5 as low-density and over 4 as very calorie-dense. This is useful both for genuine formulation comparisons across products of different serving sizes and as a sanity check — a value far outside typical ranges often signals an input error, like grams and milligrams mixed up, rather than an oddly dense food.