Grams of Protein to Calories Converter
Convert grams of protein into calories in one click, and see how much of your daily energy intake comes from protein.
Convert Protein to Calories
Enter your protein amount in grams or ounces. Add your daily calorie target to see what percentage protein makes up, and split it across your meals.
Protein Calorie Converter
Protein provides about 4 calories per gram.
How the Conversion Works
What to know about protein and calories
The 4 kcal Factor
Protein and carbohydrate both supply roughly 4 calories per gram, while fat supplies about 9. This is the standard Atwater factor used on food labels.
Calories to Kilojoules
Multiply kilocalories by 4.184 to get kilojoules. One gram of protein is therefore about 17 kJ.
Protein Is Not the Whole Food
Chicken, eggs or tofu also contain fat and carbs. This tool converts only the protein portion, not the full calorie count of a food.
Spread It Across Meals
Splitting protein evenly over your meals makes daily targets easier to hit. The per-meal result shows what each serving needs to provide.
Protein Grams to Calories Chart
Common protein amounts converted at 4 calories per gram.
| Protein (g) | Calories (kcal) | Kilojoules (kJ) | Example |
|---|---|---|---|
| 1 g | 4 | 17 | Base conversion |
| 10 g | 40 | 167 | Small handful of nuts |
| 20 g | 80 | 335 | A scoop of whey protein |
| 30 g | 120 | 502 | Typical post-workout serving |
| 50 g | 200 | 837 | Around two chicken breasts’ worth in part |
| 100 g | 400 | 1,674 | Common daily minimum for active adults |
| 150 g | 600 | 2,510 | Moderate-to-high daily intake |
| 200 g | 800 | 3,347 | High daily intake |
Protein Calories FAQ
Answers to the most common questions about converting protein grams to calories.
One gram of protein provides about 4 calories (kcal), or roughly 17 kilojoules. This is the standard Atwater factor used on nutrition labels.
Multiply the grams of protein by 4. For example, 100 g of protein equals 400 calories. To convert to kilojoules, multiply the calories by 4.184.
30 grams of protein contains about 120 calories (30 x 4).
Yes. Protein and carbohydrate both provide about 4 calories per gram. Fat provides about 9 calories per gram and alcohol about 7.
General guidance for adults is roughly 10% to 35% of daily calories from protein, though individual needs vary with body weight, age, activity and health. Speak to a doctor or registered dietitian for personal advice.