How filling a food is depends heavily on its energy density — the calories packed into each gram. This reference lists the kcal per 100 grams for dozens of common foods across every group, sorts them from most to least dense, and scales any food’s calories to your exact portion size.
How it works
Energy density is simply calories divided by weight, expressed here as kilocalories per 100 grams. The two biggest levers are water and fat: water adds weight but no calories, so watery vegetables sit below 30 kcal/100g, while pure fats like olive oil approach 900. Protein and carbohydrate fall in between at roughly 4 kcal per gram when dry.
The portion calculator multiplies a food’s per-100g figure by your entered weight and divides by 100:
portion_kcal = kcal_per_100g * grams / 100So 150 g of cooked white rice (130 kcal/100g) works out to about 195 kcal.
Energy density bands
Foods can be grouped into rough density bands that help with meal planning:
| Band | Range | Examples |
|---|---|---|
| Very low | Under 60 kcal/100g | Most vegetables, watery fruits, broth-based soups |
| Low | 60–150 kcal/100g | Legumes (cooked), whole fruit, low-fat dairy, white fish |
| Medium | 150–300 kcal/100g | Lean meat, cooked pasta and rice, eggs, tofu |
| High | 300–500 kcal/100g | Bread, cheese, oily fish, avocado |
| Very high | Above 500 kcal/100g | Nuts, seeds, chocolate, oils, butter, biscuits |
The values above are approximate; actual figures vary by specific food and preparation method.
Why density matters for appetite and weight management
The stomach registers fullness partly based on volume and stretch — not just calories. A 500-calorie serving of oil (about 56 g) provides almost no stomach stretch and leaves most people hungry. A 500-calorie serving of boiled potatoes is roughly 450 g, filling the stomach substantially. Research on “volumetrics” eating — pioneered by Dr. Barbara Rolls at Pennsylvania State University — shows that people eating fixed amounts (by weight or volume) consume fewer calories when more of that volume comes from low-density foods, without feeling more deprived.
Practically, this means building meals around a large base of low-density foods (vegetables, legumes, lean protein cooked in minimal fat, broth) and treating high-density foods (oils, cheese, nuts, bread) as smaller accompaniments. The calorie total changes significantly while the perceived meal size stays large.
How cooking changes calorie density
Cooking method is one of the biggest practical variables:
- Boiling and steaming absorb water into the food, lowering density. Dried pasta at roughly 350 kcal/100g becomes cooked pasta at roughly 130 kcal/100g once hydrated — a large shift.
- Frying adds fat and removes water, sharply raising density. A plain potato at about 70 kcal/100g becomes thick-cut chips at roughly 270 kcal/100g and crisps at roughly 520 kcal/100g.
- Roasting and baking concentrate food by driving off water, raising density. Roasted vegetables are denser than boiled — by perhaps 20–40% — because water loss concentrates the calories.
- Drying removes almost all water, producing the highest density versions of most foods. Raisins at ~300 kcal/100g versus grapes at ~70 kcal/100g.
The table in this tool uses cooked values for foods normally eaten cooked, which makes the figures more useful for portion planning than raw weights would be.
Using the portion calculator
Enter your gram weight to see the calorie total for your actual serving of any listed food. Common reference weights to help estimate portions without scales:
- A medium-sized apple: roughly 180–200 g
- A standard chicken breast: roughly 150–200 g
- A cup of cooked rice: roughly 180–200 g
- A tablespoon of oil: roughly 14 g (and about 120 kcal)
- A handful of mixed nuts: roughly 30 g (and about 170–180 kcal)
These are approximate. Weighing food is more reliable than volume measures for calorie accuracy, especially for high-density foods where small weight differences mean large calorie differences.
Tips and notes
Volumetrics-style eating leans on low-density foods to feel full on fewer calories — pile the plate with vegetables and lean protein, and treat oils, nuts, and snacks as concentrated extras. The figures here are typical reference values and vary by brand, cut, ripeness and especially cooking method, since frying adds fat and roasting drives off water. Use them to compare foods, not as a substitute for a nutrition label.