Calculadora de porcentagem

Building a nutrition facts label from scratch

This tool is a label builder, not a calorie counter. You add the ingredients in a recipe or product, type each one's nutrient values, and it assembles a clean, FDA-style Nutrition Facts panel — the familiar black-bordered box you see on packaged food — that you can download as a PNG image. It is built for people who make food: home bakers selling at a market, small producers, recipe developers, and anyone who needs a presentable label rather than a one-off calorie estimate.

How the totals are calculated

For every nutrient — calories, total fat, saturated fat, trans fat, cholesterol, sodium, carbohydrate, fibre, sugars, protein, and the vitamins and minerals — the tool simply adds up that nutrient across all ingredients. So if three ingredients contribute 120, 90, and 45 calories, the recipe total is 255. The clever part is the per-serving division. You tell it how many servings the whole batch makes, and it divides every total by that number so the label shows what one portion delivers:

per-serving value = (sum of all ingredients) ÷ servings

Tick the Per container box and it instead shows the totals for the entire batch, labelling the panel with the number of servings per container. Switching between the two views is how a regulated label is meant to work — the consumer sees both the per-serving numbers and how many servings the package holds.

Percent Daily Value, and where it comes from

Next to each nutrient the label prints a % Daily Value, calculated as round(amount ÷ daily reference × 100). The reference figures are the standard FDA Daily Values used on US labels — for example 78 g of total fat, 2,300 mg of sodium, 275 g of carbohydrate, 28 g of fibre, 50 g of protein, and 1,300 mg of calcium, all anchored to a 2,000-calorie reference diet. The footnote on the generated label states this explicitly. A %DV tells a shopper at a glance whether a serving is "a little" or "a lot" of something: 5% or less is generally considered low, 20% or more high.

A worked example

Imagine a batch of muffins from three ingredients totalling 1,800 calories, 90 g fat, 24 g saturated fat, and 36 g protein, and you set servings to 12. The label divides each by 12, so one muffin shows 150 calories, 7.5 g fat (a %DV of round(7.5 ÷ 78 × 100) = 10%), 2 g saturated fat (10% DV), and 3 g protein. Tick "Per container" and the same panel instead reports the full 1,800 calories with "Servings per container: 12" across the top. Download the PNG and you have a print-ready label.

Use cases

• Small-batch and market sellers. Produce a consistent, professional-looking label for jams, baked goods, or sauces without design software.
• Recipe developers and bloggers. Attach an accurate per-serving panel to a published recipe.
• Meal preppers. Total a week's batch cook and see exactly what each portion contains.
• Teaching label literacy. Build a label live to show how serving size changes every number on it.

Tips and common mistakes

• Source accurate ingredient data. The label is only as good as the numbers you type. Read each nutrient off the supplier's packaging or a reliable food database, and scale it to the exact quantity you actually used.
• Scale to the amount, not the package. If a bag of flour lists values per 30 g but your recipe uses 250 g, multiply before entering — the tool sums what you type, it does not know your quantities.
• Get the serving count right. Because every per-serving figure is a division by this number, an off-by-one here distorts the whole panel. Decide your real portion size first.
• This is not a regulatory submission. The panel mirrors the FDA format and uses standard Daily Values, but legal compliance (rounding rules, allergen statements, lab verification) is your responsibility. Treat the output as a presentation tool, and consult the official labelling guidance for products you sell.

This is informational, not medical or legal advice. Your ingredients and values are saved only in your own browser's local storage — nothing is uploaded — so your recipes stay private and reload when you return on the same device.