EER stands for Estimated Energy Requirement, and it represents the number of calories you need to eat each day to maintain your current body weight. It’s the official energy benchmark set by the National Academies of Sciences, Engineering, and Medicine as part of the Dietary Reference Intakes (DRIs) used in both the United States and Canada. Your EER is calculated using your age, sex, height, weight, and physical activity level.
What the EER Actually Measures
The EER is a predictive equation that estimates how many calories your body burns in a day, then tells you how many calories to consume to match that number. The goal is energy balance: calories in equals calories out, and your weight stays stable. The equations were developed using data from doubly labeled water studies, which are considered the gold standard for measuring how much energy a person actually expends over the course of a day.
The motivation behind the EER was practical. Rising rates of overweight and obesity in North America created a need for a reliable, standardized way to assess energy balance across populations. The EER gives dietitians, public health planners, and individuals a starting point for understanding calorie needs. It’s used in healthcare settings, federal nutrition policies like the U.S. Dietary Guidelines for Americans, school meal programs, and military nutrition standards.
The Three Components of Daily Energy Burn
Your total daily energy expenditure, which the EER is designed to estimate, comes from three sources. Resting energy expenditure is the biggest piece, accounting for 60 to 70 percent of the total. This is the energy your body uses just to keep you alive: breathing, circulating blood, maintaining body temperature, and running your organs.
The thermic effect of food makes up about 10 percent. This is the energy your body spends digesting, absorbing, and processing the food you eat. The remaining share comes from physical activity, which is the most variable component. For sedentary people, activity may account for as little as 15 percent of total energy expenditure. For highly active individuals, it can reach 50 percent. This wide range is exactly why the EER includes a physical activity factor in its formula.
How the EER Equation Works
The EER uses separate equations for men and women. For adults 19 and older, the formulas look like this:
- Men: 662 − (9.53 × age in years) + PA × (15.91 × weight in kg + 539.6 × height in meters)
- Women: 354 − (6.91 × age in years) + PA × (9.36 × weight in kg + 726 × height in meters)
The “PA” in those equations is a physical activity coefficient that falls into one of four categories:
- Sedentary (PA = 1.0): Only the light activity of daily living, like walking around your house or office
- Low active (PA = 1.11–1.12): Daily living plus the equivalent of walking about 1.5 to 3 miles per day at a moderate pace
- Active (PA = 1.25–1.27): Daily living plus the equivalent of walking 3 to 10 miles per day
- Very active (PA = 1.45–1.48): Daily living plus the equivalent of walking 10 or more miles per day
The slight differences in PA values between men and women reflect differences in body composition and how each sex responds metabolically to activity.
Why Age, Height, and Weight All Matter
Each variable in the equation captures something different about your metabolism. Age appears as a subtraction because your resting metabolic rate declines as you get older, meaning you burn fewer calories at rest with each passing year. Height and weight together reflect body size. Larger bodies require more energy to maintain. Your basal metabolic rate is highly dependent on both of these measurements, which is why the equation weights them heavily.
Sex matters because men and women differ in average muscle mass, fat distribution, and hormonal profiles, all of which influence how efficiently the body burns fuel. The separate equations for each sex account for these biological differences rather than trying to correct for them with a single formula.
Special Considerations for Children and Pregnancy
For children, the EER includes an additional component for growth. Kids and adolescents aren’t just maintaining their bodies; they’re building new tissue, bone, and muscle. The equations factor in the energy cost of this tissue deposition on top of what’s needed for daily activity and basic metabolism.
Pregnancy and lactation also require adjustments. The EER is defined as the intake needed to maintain energy balance for a person of a given age, sex, weight, height, activity level, and life stage. During pregnancy and breastfeeding, the “life stage” component adds calories to support fetal development, placental growth, increased blood volume, and milk production.
EER vs. TDEE
You may have seen the term TDEE (Total Daily Energy Expenditure) used in fitness apps and calorie calculators. TDEE and EER are closely related but not identical. TDEE is a general concept referring to the total number of calories your body burns in a day. The EER is a specific, standardized equation developed from peer-reviewed research that estimates TDEE and then sets it as your recommended calorie intake for weight maintenance. Think of TDEE as the idea and EER as the official, validated formula for calculating it.
Using the EER for Weight Management
The EER is designed for weight maintenance, not weight loss or weight gain. The equations predict the calorie intake that keeps your weight stable, and they do this regardless of whether your current weight is considered healthy. If you’re 200 pounds, the EER tells you how many calories to eat to stay at 200 pounds.
That said, the EER can serve as a useful starting point for weight change. The equations come with a built-in margin of error (called the standard error of predicted values), which allows planners to estimate calorie levels that would lead to weight loss or gain in most people with similar characteristics. For example, a 45-year-old man who is 5’9″, weighs 220 pounds, and is lightly active would have an EER of about 3,041 calories. Subtracting the statistical margin yields roughly 2,371 calories, a level predicted to produce weight loss in nearly all men matching his profile. That number serves as a starting point, not a rigid prescription, and would be adjusted over time based on actual results.
The key distinction is that the EER itself is a maintenance tool. It tells you where equilibrium is. What you do with that information, whether you eat at, above, or below that number, depends on your goals.