Why kcal per 100 g
Most labels publish energy as kilocalories per 100 g. This standard lets you multiply your weighed grams by the label value and divide by 100 for each item. It avoids confusion between serving sizes and different package variants.
Label reading
Check the panel for energy per 100 g and per serving. Prefer the per 100 g number. If the food is drained or cooked, confirm whether the values are for prepared or raw product. For mixed dishes, enter each component separately when possible.
Accurate weighing
Place a scale on a stable surface and tare your container. Add ingredients gradually. For oils and nut butters, measure to the gram because small changes shift totals. For liquids, grams are simpler than volume. Record as you cook.
Cooking method adjustments
Cooking does not remove calories but it can add them. Sautéing and deep frying add fat from the pan or fryer. Grilling can drip fat away. Boiling can add none. When you add oil, enter its grams. If you discard marinade or cooking liquid, do not count it.
Density vs volume
A tablespoon varies widely between ingredients. One tablespoon of oil is about 14 g but a tablespoon of chopped herbs can be only a few grams. If you rely on spoons or cups, convert them to grams using a reliable chart for your ingredient.
Worked example
Bowl for 3: 150 g cooked rice at 130 kcal per 100 g gives 195 kcal. Grilled chicken 120 g at 165 kcal per 100 g gives 198 kcal. Olive oil 15 g at 884 kcal per 100 g gives 133 kcal. Total is 526 kcal or about 175 kcal per serving. Add avocado 50 g at 160 kcal per 100 g to add 80 kcal.
Smart substitutions
Replace dense spreads with Greek yogurt, bake instead of pan fry, pick lean cuts, and bulk with vegetables or legumes. Track oils exactly. When using packaged foods, rely on the actual label for your brand and flavor.
Portion strategy
Decide your per-serving target before cooking. Build bowls around a core of vegetables, add a palm of protein, sprinkle fats thoughtfully, and check the per-serving result. Adjust with sauces at the end to land closer to your goal.
Case study
Two sauce options: mayo 30 g at 680 kcal per 100 g gives 204 kcal. Greek yogurt 40 g at 59 kcal per 100 g gives 24 kcal. The swap saves about 180 kcal total or 60 kcal per serving for three servings while taste remains similar with spice and lemon.
Assumptions and what is not included
- Calculator focuses on energy. Micronutrients are not included.
- The unit toggle converts displays between kcal and kJ only.
- Accuracy depends on your weighing and label values.
References
USDA FoodData Central | Wikipedia Calorie | Wikipedia Food energy
