EER Calculator (Estimated Energy Requirement)

What is Estimated Energy Requirement (EER)?

Estimated Energy Requirement (EER) predicts the intake needed to maintain energy balance for a person of a defined age, sex, body size, and activity category. This calculator implements the adult equations published in the 2002/2005 Dietary Reference Intakes.

The National Academies released updated Dietary Reference Intakes for Energy in 2023 with new equations derived from an expanded doubly labeled water database. The 2023 equations use activity-category-specific coefficients and should be treated as the current reference. The legacy calculator result can differ from them.

Unlike simple BMR × activity factor approaches, IOM EER equations were derived from doubly labeled water studies, a reference method for measuring total energy expenditure in free-living people over 1 to 2 weeks.

EER is the average energy intake predicted to maintain energy balance in a healthy person of given demographics and activity level. US dietary planning and nutrition policy use it as a reference.

The National Academies published separate EER equations for infants, children, pregnant women, and lactating women. Adult equations apply from age 19 onward and assume normal nutritional status without acute illness or metabolic disease.

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IOM EER equations for adults

For men 19 and older: EER = 662 − 9.53 × age + PA × (15.91 × weight + 539.6 × height). For women 19 and older: EER = 354 − 6.91 × age + PA × (9.36 × weight + 726 × height). Weight is in kg, height in meters, age in years.

Physical activity (PA) coefficients differ by sex and activity level. Sedentary men use PA = 1.0; low active 1.11; active 1.25; very active 1.48. Sedentary women use PA = 1.0; low active 1.12; active 1.27; very active 1.45.

This calculator maps standard activity descriptions to the appropriate IOM PA coefficient and computes your EER automatically from the inputs above.

Worked legacy example for a 30-year-old woman, 65 kg and 1.65 m, classified low active: 354 − 6.91 × 30 + 1.12 × (9.36 × 65 + 726 × 1.65) = about 2,168 kcal/day. Unit errors are consequential: the legacy equation requires meters, while the 2023 equations use centimeters.

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EER vs TDEE calculators

TDEE calculators typically use Mifflin-St Jeor for resting energy and apply generic multipliers (1.2 to 1.9). EER uses IOM-specific equations with PAL coefficients calibrated against doubly labeled water data.

The two approaches often produce similar results, usually within 100 to 200 kcal for average adults. Differences emerge at extremes of body size, age, or activity level where equation structures diverge.

EER aligns with the National Academies framework used in dietary planning. When current DRI alignment matters, use the 2023 equations rather than assuming the legacy output is authoritative. Mifflin-St Jeor plus an activity factor remains common in weight-management practice.

Neither method accounts for metabolic adaptation from prior dieting. If you recently lost significant weight, both EER and Mifflin-St Jeor may overestimate your current needs until adaptation reverses.

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IOM physical activity levels explained

Sedentary or inactive means daily living without enough additional activity to enter the next category.

A universal step cutoff is not part of the equation and can misclassify people because pace, occupation, and movement economy differ. Low active: daily living plus 30 to 60 minutes of moderate activity above baseline. Active: more than 60 minutes of moderate activity daily or equivalent. Very active: vigorous training or physically demanding occupation plus regular exercise.

Choose the category that describes a typical week, including work and nonexercise movement. Overestimating PAL inflates EER and can lead to eating more than needed for weight maintenance.

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How to use an EER result

EER equals maintenance calories for weight stability. Subtract 500 kcal for moderate fat loss; add 300 to 500 kcal for weight or muscle gain. Apply the same adjustment logic as with any TDEE estimate.

The National Academies planning process is two steps: calculate EER for the individual, then monitor body weight over time and adjust intake if undesired gain or loss occurs. No single number is a permanent prescription without feedback from the scale and intake records.

IOM also publishes EER equations for children, pregnant women, and lactating women with different coefficient sets. This calculator covers adults 19 and older.

As with all predictive equations, validate EER against real-world tracking. If weight trends contradict the prediction after 2 to 3 weeks of accurate logging, adjust intake based on observed balance rather than formula output alone.

Public health programs, school meal planning, and military ration design reference IOM EER values. Understanding EER helps when comparing your personal needs to population-level dietary recommendations in the USDA Dietary Guidelines.

Registered dietitians use EER when designing meal plans for institutions and clinical populations. Individual athletes and dieters may find Mifflin-St Jeor more practical. EER remains the public-health reference point.

First confirm whether you need the legacy output shown by this calculator or the current 2023 DRI value. Select activity from the whole pattern of work, transport, household movement, and exercise. Do not add routine exercise calories to an EER that already includes activity.

Round the result to a practical starting intake and keep activity reasonably stable for 14 to 28 days. Compare seven-day average weights rather than single readings. Adjust from observed energy balance when the trend contradicts the prediction.

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What changed in the 2023 DRI equations

The 2023 committee assembled an expanded doubly labeled water database and fit adult equations separately by activity category. For adult men classified inactive, EER = 753.07 − 10.83 × age + 6.50 × height in cm + 14.10 × weight in kg. Other categories use different intercepts and body-size coefficients.

For adult women classified inactive, EER = 584.90 − 7.01 × age + 5.72 × height in cm + 11.71 × weight in kg. The low-active, active, and very-active equations use their own coefficients. This differs structurally from multiplying one body-size expression by a PA coefficient.

The report's worked example gives 2,275 kcal/day for a 22-year-old low-active woman who is 165 cm and 63 kg. Use the complete National Academies table for the applicable sex and category rather than adapting one example.

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Validate EER with real weight trends

For a weight-stable adult, total expenditure and average intake converge over time. Log intake and morning weight, then compare weekly averages for at least two weeks.

Sodium, glycogen, bowel contents, and menstrual cycle phase can hide the direction over shorter periods. If EER is 2,300 kcal but weight remains stable at a carefully logged 2,100 kcal, use the observed intake as the stronger personal estimate after checking activity and logging.

If weight changes, adjust by 100 to 200 kcal and repeat. A rough trend calculation can estimate expenditure, but tissue composition makes it approximate. Recalculate after material weight, activity, or life-stage change. The DRI itself directs users to monitor weight and adjust when the prediction misses actual balance.

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Population limits and clinical caveats

EER equations estimate healthy populations and carry prediction error for individuals. Activity classification can be wrong, and doubly labeled water measures total expenditure over a period rather than prescribing an exact daily intake.

The adult equations here are not the pediatric, pregnancy, or lactation equations. Acute illness, severe malnutrition, major burns, edema, and recovery from surgery require clinical assessment. Athletes may need sport-specific fueling beyond weight maintenance.

Seek professional guidance for unexplained weight change, eating-disorder history, diabetes medication, kidney disease, pregnancy, or symptoms of inadequate intake. A public-health reference does not override symptoms, treatment, or measured clinical needs.

Report the result as an estimate rounded to a usable interval. The uncertainty from activity classification and individual variation is larger than the final digit displayed by the equation.

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How it works

IOM EER equations (2005) incorporate PA coefficients specific to sex and activity level.

Frequently asked questions

• EER vs TDEE?EER is the official IOM estimate. TDEE via Mifflin-St Jeor is similar but uses different activity multipliers.

Related calculators

References

1. National Academies. Dietary Reference Intakes for Energy - Summary
2. USDA/HHS. Dietary Guidelines for Americans
3. Mifflin et al.. A new predictive equation for resting energy expenditure in healthy individuals
4. Frankenfield et al.. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults
5. HHS. Physical Activity Guidelines for Americans
6. CDC. Healthy Weight
7. National Academies. Dietary Reference Intakes for Energy, 2023