Protein, Energy and BMI Calculator

Enter the data below to receive estimated daily protein and calorie needs for healthy adults, as well as Body Mass Index (BMI).

Units: Standard    Metric
Weight: (pounds)
* Please choose an age greater
than 18 years
Gender: Male    Female
Activity Level Factor:
Percent of Calories
from Protein:
%  (Please choose a number between 10% and 35%)

Scientific evidence suggests that moderately increasing the proportion of protein in the diet may improve body composition, facilitate weight loss and improve weight maintenance following weight loss. Most research showing positive effects looked at diets with protein levels at the high end of the Acceptable Macronutrient Distribution Range (AMDR): 20 - 35 percent of calories from protein.

Estimated daily protein needs:  grams
Estimated daily calorie needs:  calories

About this Calculator

Percent of Calories from Protein: Using a factor of 10 – 35 percent of calories from protein is recommended based on the Acceptable Macronutrient Distribution Range (AMDR) for adults, developed by the Food and Nutrition Board of the Institute of Medicine, National Academies.1 AMDRs are ranges of intakes for macronutrients expressed as a percentage of total energy; for adults, the AMDR for carbohydrates = 45 - 65 percent of calories and the AMDR for fat = 20 - 35 percent of calories.

Activity Level Factor: Calorie needs aren’t based on height, weight, age and gender alone. Adding an Activity Level Factor accounts for calorie needs above and beyond the amount needed at rest.

Estimated Daily Protein Needs: Estimated Daily Protein Needs (grams) = Percent of Calories from Protein divided by 4 because there are 4 calories in a gram of protein.

Estimated Daily Calorie Needs: Estimated Daily Calorie Needs = Resting Energy Expenditure (REE) multiplied by the Activity Level Factor selected. This calculator uses the Mifflin/St. Jeor formula to calculate REE.2

BMI (Body Mass Index): BMI is a measure of body fat based on height and weight that applies to adult men and women. BMI Categories: Underweight = <18.5; Normal weight = 18.5–24.9; Overweight = 25–29.9; Obesity = BMI of 30 or greater.3

1 Food and Nutrition Board, Institute of Medicine, National Academies. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2002/2005). Dietary Reference Intakes (DRIs): Acceptable Macronutrient Distribution Ranges. Available at: Accessed September 28, 2010.
2 MD Mifflin, ST St Jeor, LA Hill, BJ Scott, SA Daugherty and YO Koh. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, Vol 51, 241-247, Copyright © 1990. Available at: Accessed September 28, 2010.
3 National Heart, Lung, and Blood Institute/National Institutes of Health. Calculate Your Body Mass Index. Available at: Accessed September 28, 2010.