Enter the total daily calorie intake and the desired nutrient (Carbs, Protein, or Fat) into the calculator to determine the daily intake. This calculator can also evaluate any of the variables given the others are known.

40 40 20 Diet Calculator

Enter Calories (kcal) to calculate 40/40/20 macro grams, or enter Carbs + Protein + Fat (grams) to calculate Calories and your macro split.

Important: This calculator is for educational use only and is not medical advice. Calorie and macronutrient needs vary by age, health conditions (including kidney disease), activity level, pregnancy, and goals—consider personalized guidance from a registered dietitian/clinician, especially before using a very low-calorie intake. Nutrition label “Calories” are kilocalories (kcal). For general macro range guidance, check the Dietary Guidelines for Americans (AMDR) and NIH/MedlinePlus.

40 40 20 Diet Formula

The following formula is used to calculate the daily intake for a 40 40 20 diet.

CI = (TDC × 0.40) / 4 for Carbs and Protein, (TDC × 0.20) / 9 for Fat

Variables:

  • CI is the daily intake in grams for Carbs, Protein or Fat
  • TDC is the total daily calorie intake (Calories/kcal)

To calculate the daily intake for Carbs and Protein, multiply the total daily calorie intake by 0.40, then divide the result by 4. To calculate the daily intake for Fat, multiply the total daily calorie intake by 0.20, then divide the result by 9. This is because each gram of Carbs and Protein contains 4 Calories (kcal), while each gram of Fat contains 9 Calories (kcal).

What is a 40 40 20 Diet?

A 40 40 20 diet is a bodybuilding-style macro target that divides daily calorie intake into 40% carbohydrates, 40% protein, and 20% fat. Because it is relatively high in protein compared with common population-level guideline ranges (such as the AMDR), it’s best viewed as one possible approach some athletes use rather than a universal template for everyone.

How to Calculate 40 40 20 Diet?

The following steps outline how to calculate the daily intake for Carbs, Protein, and Fat in a 40 40 20 Diet.

  1. First, determine the total daily calorie intake (TDC) in Calories (kcal).
  2. Next, calculate the daily intake for Carbs and Protein using the formula: CI = (TDC × 0.40) / 4.
  3. Then, calculate the daily intake for Fat using the formula: CI = (TDC × 0.20) / 9.
  4. Finally, calculate the daily intake for Carbs, Protein, and Fat.
  5. After inserting the TDC value and calculating the results, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge:

Total daily calorie intake (TDC) = 2000 calories