Energy estimate
TDEE Calculator: Resting and Daily Energy Estimates
Estimate resting energy with Mifflin-St Jeor and daily energy with the 2023 NASEM adult equations, with assumptions and uncertainty shown.
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Your assumptions
Build the estimate
For adults aged 19–78
Estimated result
This is not an intake target or a weight-change prediction.
The daily estimate uses the 2023 NASEM adult equation for the selected activity category. It is calculated independently from the resting estimate, rounded, and should not be treated as an exact intake target.
- Equation term
- Activity range
Method
What is being calculated?
The Mifflin-St Jeor equation estimates resting energy expenditure from age, height, weight, and one of the two sex-labelled constants in the published formula. The study derived the equation from 498 healthy adults aged 19–78.
The daily estimate uses the separate 2023 NASEM adult EER equation for the selected physical activity category. We do not multiply the Mifflin result by an unrelated activity factor.
Limits
What can this estimate not tell you?
It cannot observe what you actually ate or did, measure your metabolism, diagnose a condition, or prescribe a calorie deficit or macro plan. This general tool excludes minors, pregnancy or lactation, and medical use. Results may also be less representative with atypical body composition.
In the NASEM report, adult equation prediction error was summarized with root mean square errors of 339 kcal/day for males and 246 kcal/day for females. Those are model-level error summaries, not an individual confidence interval; choosing the wrong activity category adds more uncertainty.
Use a qualified health professional for medical or nutrition decisions that depend on an individual measurement.
From estimate to everyday context
A static number cannot see what happened today
Grio can use what you log and supported daily context to shape the burden and timing of a next action. It does not rewrite calorie or macro targets because of one poor night of sleep.
Sources and review notes
Content reviewed August 28, 2026
- Mifflin et al. (1990), A new predictive equation for resting energy expenditure in healthy individuals American Journal of Clinical Nutrition · accessed August 18, 2026
- Equations to estimate energy requirement Health Canada, based on the 2023 NASEM Dietary Reference Intakes · accessed August 18, 2026
- Dietary Reference Intakes for Energy National Academies of Sciences, Engineering, and Medicine (2023) · accessed August 18, 2026