Kcal Proteína
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The Kcal Protein calculator estimates food calories based on protein content. It uses the standard 4 calories per gram of protein, common in nutrition. Useful for estimating energy from meats, eggs, legumes, and high-protein foods.
To use, enter protein grams per 100g of food. For example, 20g of chicken breast (20g/100g) = 20g × 4 kcal/g = 80 kcal. Ideal for meal planning, daily intake tracking, or comparing protein sources.
Important note: actual calories vary due to fat and carbs. Cheese or eggs have calories beyond protein. Use as a starting guide, but check labels or consult nutritionists for accuracy.
The calculator helps compare protein sources. 100g lentils (18g protein) = 72 kcal vs. 100g salmon (20g) = 80 kcal. Valuable for vegetarian diets, weight loss, or muscle gain.
Frequently asked questions
How does the calculator work?
It multiplies protein grams by 4 kcal/g, the standard nutrition rule for protein calories.
Do I consider only protein?
No. Foods like cheese or eggs also have fat calories. The calculator shows only the protein portion.
Can I use it for processed foods?
Yes, but check the label for accurate protein content per 100g to input correctly.
Why does the result differ from labels?
Because real foods contain other nutrients (fats, carbs) that contribute to total calories.
How many calories in 50g of chicken?
If 100g chicken has 20g protein, 50g will have 10g × 4 = 40 kcal from protein only.