Food Calorie Density Calculator
Calorie density, the calories in a food per gram of its weight, is a simple and powerful way to compare how filling foods are for the same calories. Water-rich vegetables sit low; oils and dry, fatty foods sit high. This calculator takes a food's total calories and weight in grams and returns its density per gram and per 100 grams, then computes the calories in any serving weight you enter. Use figures from a Nutrition Facts label or USDA FoodData Central for accuracy. The arithmetic is exact; the nutrition numbers come from your source.
Calorie density formula
calories per gram = total calories / weight (g)
calories per 100 g = calories per gram * 100
calories in serving = calories per gram * serving weight
band: low < 1.0, medium 1.0 to 4.0, high > 4.0 cal/g
The density band is a common rough classification. Use it as a guide, not a strict cutoff.
Calorie density context
- Below about 1 calorie per gram: low density (most vegetables, broth soups, many fruits).
- About 1 to 4 calories per gram: medium density.
- Above about 4 calories per gram: high density (oils, nuts, many snacks).
- Pure fat is about 9 calories per gram; protein and carbohydrate about 4.
- Use label or USDA FoodData Central figures for accuracy.
Calorie density: frequently asked questions
What is calorie density?
Calorie density is the number of calories per unit weight of a food, usually expressed as calories per gram or per 100 grams. Water-rich foods like vegetables and fruit have low calorie density; fats and dry, oily foods have high calorie density. It is a useful lens for managing how filling a meal is per calorie.
How is calorie density calculated?
Divide the food's total calories by its weight in grams. A 200 gram portion with 300 calories has a density of 1.5 calories per gram, or 150 calories per 100 grams. Use the calories and weight from a nutrition label or the USDA FoodData Central entry for accuracy.
What is a low calorie density food?
Foods below about 1 calorie per gram are considered low density: most non-starchy vegetables, broth-based soups and many fruits. Foods above about 4 calories per gram, such as oils, nuts and many snack foods, are high density. The exact thresholds are a guideline, not a rule.
Where do I get calorie and weight figures?
Use the product's Nutrition Facts label or look the food up in USDA FoodData Central, which publishes calories per 100 grams for thousands of foods. Enter the total calories and the matching weight; the calculator handles any units as long as weight is in grams.
How do I find calories in a specific serving?
Enter your serving weight and the calculator multiplies the calorie density by that weight to give the calories in that serving. This lets you size a portion to a calorie target, or compare two foods at the same weight.
Official sources
- USDA: FoodData Central (calories per 100 g).
- FDA: U.S. Food and Drug Administration (Nutrition Facts label).
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.