EER Calculator (Estimated Energy Requirement)

The Estimated Energy Requirement (EER) is the average daily dietary energy intake needed to maintain energy balance in a healthy, normal-weight individual of a given age, sex, weight, height, and physical activity level. It was developed by the Institute of Medicine (IOM) and is widely used in nutrition science and dietetics.

EER is calculated using sex-specific formulas from the IOM. For males: EER = 662 − (9.53 × Age) + PA × [(15.91 × Weight in kg) + (539.6 × Height in m)]. For females: EER = 354 − (6.91 × Age) + PA × [(9.36 × Weight in kg) + (726 × Height in m)]. The PA value is a physical activity coefficient that ranges from 1.0 (sedentary) to 1.48 (very active) for males and 1.0 to 1.45 for females.

Using the female EER formula with a Low Active PA coefficient (1.12): EER = 354 − (6.91 × 45) + 1.12 × [(9.36 × 70) + (726 × 1.65)] = 354 − 310.95 + 1.12 × [655.2 + 1197.9] ≈ 354 − 310.95 + 2075.6 ≈ 2,118 kcal/day. This is the estimated daily calorie intake to maintain her current weight.

EER (Estimated Energy Requirement) is based on a validated predictive equation from the IOM designed for healthy, normal-weight individuals and accounts for age, sex, weight, height, and physical activity. TDEE (Total Daily Energy Expenditure) is a broader term often calculated using other equations (like Mifflin-St Jeor) combined with activity multipliers. Both aim to estimate maintenance calories, but EER uses a more research-derived approach specific to energy balance science.

BMI itself is not a direct input in the EER formula, but weight and height — the two components used to calculate BMI — are both used. Since EER is designed for healthy, normal-weight individuals, it may not be fully accurate for people with obesity or those significantly underweight. In such cases, consulting a registered dietitian for an individualized assessment is recommended.

Choose Sedentary if you have little or no structured exercise. Low Active covers light activity like walking or light exercise 1–3 days per week. Active means moderate exercise 3–5 days per week. Very Active applies if you engage in intense physical labor or hard training 6–7 days per week. When in doubt, most lightly active adults fall into the Low Active category.

This calculator provides a base EER for non-pregnant adults. Pregnant and breastfeeding women have additional energy needs on top of their standard EER. The IOM recommends adding approximately 340 kcal/day during the second trimester, 452 kcal/day in the third trimester, and around 500 kcal/day while breastfeeding. Always consult a healthcare provider for guidance during pregnancy or lactation.

EER represents the calories needed to maintain your current weight — it is not a weight loss or gain target. To lose weight, you would generally aim to eat below your EER; to gain weight, above it. A deficit or surplus of approximately 500 kcal/day is commonly used as a starting point, but individual responses vary and professional guidance is always advisable.