Clinical TDEE Calculator
Fuel & FastingRESULT IN KCAL / DAY
Total daily energy expenditure from the Mifflin–St Jeor equation — your evidence-based starting point for fat loss or muscle gain.
Editorial & evidence standards
Built on peer-reviewed equations
Mifflin–St Jeor (1990) & Katch–McArdle, validated against indirect-calorimetry studies (Frankenfield 2005) · independent RD review pending
Updated June 2026
Inputs
Sample numbersBiological sex
Unit system
32 yrs
172 lb
ft / in
ft
in
Activity level
Goal
AffiliateCONTEXTUAL
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Shown for convenience only — informational, not medical advice or an endorsement.
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Where your daily energy goes
At this activity level your body burns about 2,694 kcal/day just to maintain weight. Here’s how that splits across the three components of total daily energy expenditure — it updates the instant you change an input.
Resting metabolism (BMR)
1,738kcal · 65%
Energy to keep you alive at rest — breathing, circulation, brain and organ function.
Activity (NEAT + exercise)
687kcal · 26%
Workouts plus all non-exercise movement: walking, fidgeting, standing, chores.
Thermic effect of food
269kcal · 10%
Calories spent digesting and processing meals — about 10% of intake.
TEF is estimated at ~10% of maintenance, a standard textbook approximation; activity is the remainder once BMR and TEF are accounted for. Your goal target (2,694 kcal) adjusts up or down from this maintenance figure.
Methodology & Sources · E-E-A-T Cited
How the TDEE calculator works
Built on peer-reviewed predictive equations and independently cross-checked against indirect-calorimetry studies — so the number you get is defensible, not a guess.
Key takeaways
- Two-part formula — your TDEE is your basal metabolic rate (BMR) multiplied by an activity factor between 1.2 and 1.9.
- Most accurate default — Mifflin–St Jeor has the lowest error of any predictive BMR equation for non-obese adults, which is why clinicians use it.
- A precise starting point, not a fixed truth — predictive equations carry a ±10% margin, so adjust from your real 2–3 week weight trend.
- Body-composition aware — adding a body-fat % switches the engine to Katch–McArdle, which scales metabolism to your lean mass.
- Recalculate as you change — a lighter body burns fewer calories, so refresh your TDEE roughly every 4–5 kg of weight change.
01
What is TDEE?
Total Daily Energy Expenditure (TDEE) is the total number of calories your body uses across a full day. It bundles three things: your basal metabolic rate (the energy needed just to stay alive at rest), the energy cost of moving and exercising, and the smaller amount burned digesting food. For anyone trying to change their body composition, TDEE is the single most useful number — it is the line between a calorie surplus and a calorie deficit.
Because TDEE depends on body size, sex, age and activity, there is no universal figure. A larger, younger, more active person burns far more than a smaller, older, sedentary one. This calculator personalises the estimate from your own inputs so the result reflects you rather than a population average.
02
How it is calculated
Clinarix first estimates your basal metabolic rate (BMR) with the Mifflin–St Jeor equation: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + a sex constant (+5 for men, −161 for women). Across the common predictive equations, Mifflin–St Jeor has the smallest error versus laboratory measurement for non-obese adults, which is why it is the default in clinical and sports-nutrition practice.
BMR is then multiplied by an activity factor — 1.2 (sedentary) up to 1.9 (athlete) — to give maintenance calories, the amount that holds your weight steady. Finally, your goal shifts the target: a cut applies roughly a 20% deficit, maintenance leaves it unchanged, and a lean bulk adds about a 12% surplus. If you supply a body-fat percentage under Advanced, the tool switches to the Katch–McArdle equation, which scales BMR to lean mass and is more accurate for lean, muscular individuals.
Mifflin–St Jeor
BMR = 10·kg + 6.25·cm − 5·age + s
s = +5 (male) · −161 (female). Lowest published error for non-obese adults.
Katch–McArdle
BMR = 370 + 21.6 × lean mass (kg)
Scales to lean mass — more accurate for lean, muscular bodies.
03
How to use your result
Treat the number as a precise starting point, not a fixed truth. Predictive equations carry roughly a ±10% margin against indirect calorimetry, so eat at your target for two to three weeks and watch the trend. If your weight is not moving the way the goal predicts, adjust intake by about 100–150 kcal and reassess. Clinarix tracks this automatically in your Wellness Snapshot so the estimate keeps tightening over time.
Recalculate after every 4–5 kg of weight change — a lighter body burns fewer calories, so yesterday's TDEE will overestimate today's. Your macro split (protein anchored to bodyweight, fat near 27% of calories, carbohydrate filling the rest) is derived from the same target, so the whole plan stays internally consistent.
Who should not rely on this estimate?
Predictive equations lose accuracy during pregnancy and lactation, in severe obesity (BMI > 40), at the extremes of muscularity, and with thyroid or other metabolic conditions or medications that alter resting metabolism. People recovering from eating disorders should not use calorie targets without clinical supervision. In any of these situations, use indirect calorimetry and work with a licensed clinician or registered dietitian rather than relying on this calculator alone.
Citations · peer-reviewed sources
- 1
Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247.
- 2
Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775–789.
- 3
McArdle WD, Katch FI, Katch VL. Essentials of Exercise Physiology. Wolters Kluwer / Lippincott Williams & Wilkins. (Katch–McArdle lean-body-mass BMR equation, applied when a body-fat % is supplied.)
Textbook
FAQ · AI-extractable answer block
Frequently asked questions
What is TDEE and why does it matter?
TDEE — Total Daily Energy Expenditure — is how many calories you burn per day across rest and activity. It is the most important number for fat loss or muscle gain: eat below it to lose weight, above it to gain. Clinarix calculates it from your age, weight, height, sex and activity level.
How many calories should I eat to lose weight?
For sustainable fat loss, eat about 10–20% below your TDEE — a deficit of roughly 300–500 kcal/day yields about 0.25–0.5 kg of fat loss per week. Larger deficits risk muscle loss. Clinarix sets your cut target automatically when you choose the "Cut" goal.
How accurate is a TDEE calculator?
A Mifflin–St Jeor TDEE estimate is accurate to within about ±10% for most healthy adults. Treat it as a precise starting point, then adjust by roughly 100 kcal if your real-world weight trend over 2–3 weeks differs from the prediction.
Does entering my body fat percentage change the result?
Yes. When you add a body-fat percentage under Advanced, the calculator switches from Mifflin–St Jeor to the Katch–McArdle equation, which bases your metabolism on lean mass. This is more accurate for lean, muscular people whose body composition differs from the population average.
Should I recalculate my TDEE as I lose weight?
Yes. TDEE falls as you lose weight because a lighter body burns fewer calories. Recalculate every 4–5 kg of change, or let Clinarix update it automatically from your connected profile so your targets stay current.
Is the TDEE calculator free?
Yes — every Clinarix calculator is free. Pro ($9/mo) adds unlimited longitudinal trends, AI insights and detailed reports, but your TDEE result is always free.
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Important: This calculator provides general educational estimates and is not medical advice, diagnosis, or treatment. Predictive equations carry roughly a ±10% margin and are not a substitute for assessment by a licensed clinician or registered dietitian. Consult a qualified professional before making changes to your diet, especially if you have a medical condition, are pregnant or breastfeeding.