DRI Calculator

Estimate your Dietary Reference Intake: daily calorie needs (EER), protein RDA, and carbohydrate/fat AMDR ranges from your age, sex, weight, height, and activity level.

Quick Facts

EER (adults, IOM 2005)
Men: 662 − 9.53×age + PA×(15.91×kg + 539.6×m)
Women: 354 − 6.91×age + PA×(9.36×kg + 726×m). PA is the physical-activity coefficient.
Protein RDA
0.8 g per kg body weight/day
Minimum for the average sedentary adult; athletes, older adults, and pregnancy need more.
Macronutrient AMDR
Carb 45–65% • Fat 20–35% • Protein 10–35% of calories
Acceptable Macronutrient Distribution Ranges, IOM 2005.
Fiber Adequate Intake
38g/30g (men) • 25g/21g (women)
Ages 19–50 vs. 51+, respectively.

Your Results

Calculated
Estimated Energy Requirement
-
Calories/day to maintain current weight (EER)
Protein RDA
-
0.8 g per kg body weight/day
Carbohydrate AMDR
-
45–65% of calories, at 4 kcal/g
Fat AMDR
-
20–35% of calories, at 9 kcal/g

Ready

Enter your age, sex, weight, height, and activity level, then press Calculate.

Formula and Method for the DRI Calculator

Dietary Reference Intakes (DRI) are the nutrient recommendation values published by the Institute of Medicine (now part of the National Academies of Sciences, Engineering, and Medicine). This calculator focuses on the DRI components that depend most directly on your personal profile: Estimated Energy Requirement (EER, your maintenance calorie level), the Recommended Dietary Allowance (RDA) for protein, and the Acceptable Macronutrient Distribution Ranges (AMDR) for carbohydrate and fat. It applies to adults age 19 and up, since the EER equations below were derived and validated for that age range.

How the calculation works

First, your weight and height are converted to kilograms and meters. A physical activity (PA) coefficient is selected based on your sex and activity level (Sedentary = 1.00 for both sexes; Low Active = 1.11 men / 1.12 women; Active = 1.25 men / 1.27 women; Very Active = 1.48 men / 1.45 women). These feed the IOM 2005 EER equations: for men, EER = 662 − 9.53×age + PA×(15.91×weight[kg] + 539.6×height[m]); for women, EER = 354 − 6.91×age + PA×(9.36×weight[kg] + 726×height[m]). Protein RDA is then calculated as 0.8 g per kilogram of body weight. Finally, the carbohydrate range is 45–65% of EER divided by 4 kcal per gram, and the fat range is 20–35% of EER divided by 9 kcal per gram (the AMDR set by the IOM for adults).

Common mistakes

  • Treating EER as a weight-loss target: EER estimates the calories needed to maintain your current weight at your current activity level — losing weight requires a deliberate deficit below EER, not eating at EER.
  • Using 0.8 g/kg as a ceiling instead of a floor: the RDA is the minimum that prevents deficiency in a sedentary adult; strength athletes, endurance athletes, older adults, and those recovering from illness commonly need 1.2–2.0 g/kg.
  • Mismatched units: enter weight and height with the unit selector set correctly — a value entered as centimeters but read as inches (or vice versa) throws off every downstream result.

Real-world applications

  • Setting a starting daily calorie target before adjusting up or down for a weight-gain or weight-loss goal.
  • Checking whether a diet or meal plan's macronutrient split falls inside the evidence-based AMDR ranges.
  • Estimating protein needs for general health versus higher targets used in athletic or clinical nutrition plans.
  • Cross-checking fiber intake against the age- and sex-specific Adequate Intake values.

This calculator provides educational estimates based on population-level DRI formulas. It is not personalized medical or nutrition advice — individuals with medical conditions, who are pregnant or breastfeeding, or with unusual body compositions should consult a registered dietitian or physician for individualized targets.

Frequently Asked Questions

What does "DRI" stand for and what does this calculator estimate?
DRI stands for Dietary Reference Intake, the umbrella term the Institute of Medicine (now the National Academies of Sciences, Engineering, and Medicine) uses for nutrient recommendations. This calculator estimates your Estimated Energy Requirement (EER, in calories/day), your protein RDA, and Acceptable Macronutrient Distribution Range (AMDR) targets for carbohydrate and fat, based on your age, sex, weight, height, and activity level.
How is the Estimated Energy Requirement (EER) calculated?
For adults, the IOM 2005 equations are: Men, EER = 662 − 9.53×age + PA×(15.91×weight[kg] + 539.6×height[m]); Women, EER = 354 − 6.91×age + PA×(9.36×weight[kg] + 726×height[m]). PA is a physical activity coefficient (1.00 sedentary up to 1.45–1.48 very active) that scales the weight and height terms.
How much protein do I need per day?
The RDA for protein is 0.8 grams per kilogram of body weight per day for the average sedentary adult — enough to prevent deficiency, not necessarily optimal for muscle building or older adults. The broader AMDR allows protein to make up 10–35% of total calories; athletes, older adults, and people recovering from illness often need more than the 0.8 g/kg minimum.
Why do carbohydrate and fat show as a range instead of one number?
The Institute of Medicine defines Acceptable Macronutrient Distribution Ranges (AMDR) rather than single targets: 45–65% of calories from carbohydrate and 20–35% from fat for adults. Any combination inside those ranges is considered consistent with reduced chronic disease risk, so the calculator reports the full gram range rather than a single value.

Related calculators