Bar Nutrition Calculator

Bars are among the most convenient ways to get protein, energy, or a quick snack on the go — yet a chocolate bar, a granola bar, and a protein bar can differ by hundreds of calories per 100 g. This calculator estimates the calories, protein, carbohydrates, fat, fiber, and sugar in the bar you are eating, using typical per-100 g values for six common bar categories.

Choose the bar type, enter the weight printed on the wrapper (usually 30–80 g), and set how many bars you plan to eat. The tool works out nutrition for a single bar and for the whole serving, then shows where the calories come from — protein, carbs, or fat. It is useful for gym nutrition, meal prep, weight management, or comparing two products before you buy.

🍫 Bar Nutrition Calculator

Estimate calories, protein, carbs, fat, fiber, and sugar for protein bars, granola bars, energy bars, and more.

Bar type

Weight per bar (g)

Number of bars

📊 Your Bar Nutrition

Total per serving— kcal

Protein— g

Carbs— g

Fat— g

Fiber— g

Sugar— g

Calorie splitProtein —% · Carbs —% · Fat —%

Calories per 100 g—

Protein per 100 g—

Step-by-step

Step-by-Step Guide

Using the calculator takes about ten seconds. First, pick the bar type that matches your wrapper as closely as possible — protein bars, granola bars, energy bars, cereal bars, chocolate bars, and fruit-and-nut bars use different baseline values. Then enter the net weight printed on the front of the pack (usually 30–80 g), set how many bars you ate or plan to eat, and press Calculate Nutrition.

Pick the bar type from the dropdown.
Enter the weight in grams, or tap a preset (40 / 50 / 60 / 80 g).
Set the number of bars in your serving.
Press Calculate Nutrition and read the totals, per-100 g figures, and calorie split.

Tip: if your label shows per-bar figures, sanity-check the result — most full-size protein bars weigh 50–60 g, while mini and cereal bars are usually 20–40 g.

How the Estimates Work

Each bar category is described by average values per 100 g. The calculator scales those values linearly by the weight you enter, then multiplies by the number of bars. Calories are estimated from the macros using standard Atwater factors — 4 kcal per gram of protein, 4 kcal per gram of carbohydrate, and 9 kcal per gram of fat — which is why the calorie split always adds up to roughly 100%.

Because real bars vary by brand, recipe, and coating, treat results as estimates within roughly ±10–15% of the printed label.

Worked Example

You eat a 60 g chocolate bar. The reference values for chocolate bars are 535 kcal, 7 g protein, 60 g carbs, and 30 g fat per 100 g. Multiplying by 0.6 gives 321 kcal, 4.2 g protein, 36 g carbs, and 18 g fat per bar. The calorie split works out to about 5% protein, 45% carbs, and 50% fat — typical for a treat-style bar.

Reference Values (per 100 g)

Bar type	kcal	Protein	Carbs	Fat	Fiber	Sugar
Protein bar	375	35 g	40 g	12 g	5 g	18 g
Granola bar	450	7 g	67 g	18 g	4 g	25 g
Energy bar	400	10 g	65 g	10 g	5 g	20 g
Cereal bar	400	5 g	75 g	9 g	3 g	30 g
Chocolate bar	535	7 g	60 g	30 g	3 g	50 g
Fruit & nut bar	470	10 g	55 g	22 g	7 g	25 g

Limitations & Accuracy Notes

Manufacturers are allowed small tolerances on nutrition labels, and the net weight is not always the same as the edible weight when a bar contains large chunks or a thick coating. Sugar alcohols and high-fiber sweeteners can also change the true energy content slightly. If you track carbohydrates for medical reasons, always use the label of the exact product you are eating rather than a category average.

This tool gives category-level estimates only — it is not a medical or dietary prescription.

For more detail on reading labels, see the FDA's guide to the Nutrition Facts label.