Nutrition calculator
Calorie Density Calculator
Compare foods and meals by calories per gram, calories per 100 g and estimated calories per serving so portion decisions are easier to understand.
On this page
Convert known food energy to a common weight
Enter an already-known energy total and the weight of that same food. This calculator divides and rescales those values; it does not look up ingredients or estimate energy from a food name.
Formulas
Calorie density in kcal/g = total food kcal ÷ food weight in g. Energy per 100 g = kcal/g × 100. Planned serving kcal = kcal/g × planned serving grams.
Use matching energy and weight
- Enter the calories for the exact quantity of food being weighed. Calories here means kilocalories (kcal), not kilojoules.
- Enter that food's weight in g, using the same cooked, drained or raw state as the energy information.
- Enter a planned portion in g to scale the result to that portion.
- Choose Meal, Snack or Ingredient as a record note. Food type changes only the displayed note; it does not alter the calculation or category.
This tool's descriptive categories
- Low: less than 1 kcal/g.
- Moderate: at least 1 but less than 2.5 kcal/g.
- High: at least 2.5 but less than 4 kcal/g.
- Very high: at least 4 kcal/g.
These are the calculator's own descriptive bins, not diagnostic or official dietary cut-offs. Classification uses the unrounded kcal/g value.
Worked density and portion examples
Scale a known portion
A 200 g food with 250 kcal has 250 ÷ 200 = 1.25 kcal/g, or 125 kcal per 100 g. A planned 150 g portion has 1.25 × 150 = 187.5 kcal, displayed as 188 kcal. Its density falls in this tool's Moderate category.
Compare equal calories by weight
A 250 kcal snack weighing 50 g has 500 kcal per 100 g. A 250 kcal bowl weighing 300 g has about 83 kcal per 100 g. Their original energy totals are equal; their food weights differ.
Keep a cooked recipe consistent
A finished recipe containing 650 kcal and weighing 550 g has about 118 kcal per 100 g. Use the finished recipe's total energy and weight together, including any retained oils or sauces.
Avoid mismatched food quantities
- Using calories for one labelled serving with the weight of the whole package.
- Entering kilojoules into the kcal field.
- Pairing raw-food calories with cooked weight after water has been gained or lost.
- Forgetting oil, sauces or other energy sources retained in the food.
- Treating the density category as a measure of protein, fibre, micronutrients or overall food quality.
What a weight-based comparison leaves out
Energy per gram provides a consistent basis for comparing portions. It does not predict how filling a particular meal will be, establish an appropriate portion for an individual or describe the balance of nutrients. Higher-density foods can still make useful contributions to a diet.
Cooking, draining and preparation change food weight and sometimes retained energy. The calculation is only as reliable as the paired energy and weight entries. Results round kcal/g to two decimals and kcal per 100 g and planned-serving energy to whole kcal.
Calorie Density Calculator FAQs
Does Food type change the result?
No. Meal, Snack and Ingredient are displayed as a note. Energy, weight and planned serving determine the numeric results; kcal/g determines the descriptive category.
What happens exactly at a category boundary?
At 1 kcal/g the category is Moderate, at 2.5 it is High and at 4 it is Very high. These bins are tool-specific and use the unrounded value.
Should I use raw or cooked weight?
Use whichever state matches the calorie total you enter. For a finished recipe, pair finished weight with that recipe’s retained total energy.
Does a lower density mean a more nutritious food?
No. Density describes energy relative to weight. It does not measure protein, fibre, vitamin content or whether a food suits your needs.
Match the energy total to the food weight
Use kcal and grams from the same quantity and preparation state. Compare the per-100-g result, then scale to the portion you intend to eat; keep the tool's category separate from broader nutrition decisions.