Body Composition Calculator

Wholeminds Interactive Tool · Sports Performance & Physical Wellness

Your metabolism is math. Your follow-through is psychology.

Most calculators hand you a number and abandon you there. This one estimates your energy needs, builds goal-specific macros, shows what protein can, and cannot, change, identifies the behavioral friction most likely to derail the plan, and converts everything into a ready-to-use AI implementation prompt.

01Licensed Professional Counselor

02NASM Certified Personal Trainer

03NASM Certified Nutrition Coach

Developed by Adam Eltouny, LPC, NASM-CPT, NASM-CNC, NASM-WLS, ACE-BCS · Updated August 29, 2026

Estimate → Experiment → Adjust

The Mifflin-St Jeor equation estimates resting energy expenditure; it does not measure your metabolism directly. Treat the result as a scientifically informed starting hypothesis, then compare it with several weeks of real-world trends rather than declaring one calculator “right” or your body “broken” (Mifflin et al., 1990; NASM, 2026a).

BodyGoalBehaviorReal life

1

Build the physiological estimate.

Your BMR is the energy required at rest. TDEE layers estimated activity on top.

Choose units

U.S. unitsPounds, feet and inches Metric unitsKilograms and centimeters

Current weight (lb)

Height (feet)

Additional inches

Age

Body-fat estimate (%) · optional Used only to show estimated lean mass, not to pretend consumer body-fat measurements are exact.

Goal/reference weight · optional Can be selected later as the protein calculation reference.

Sex-specific equation constant

Male equationMifflin-St Jeor constant: +5 Female equationMifflin-St Jeor constant: −161

This is a limitation of the equation, not a judgment about gender identity. Choose the physiological equation your clinician would use; if uncertain, calculate both and treat them as a range.

Daily activity estimate

Mostly sedentaryLittle structured exercise Lightly activeLight exercise 1-3 days/week Moderately activeModerate exercise 3-5 days/week Very activeHard exercise 6-7 days/week Extremely activePhysical job and/or twice-daily training

These are NASM-published planning multipliers. Overestimating activity is one of the easiest ways to overestimate TDEE (NASM, 2026a).

Medical and wellbeing guardrails

Select anything that may require individualized medical nutrition care. The calculator will still explain the math, but it will prominently flag the result for professional review.

Pregnant or breastfeeding Kidney disease or dialysis Liver disease Diabetes or glucose-lowering medication Current/past eating disorder or food-tracking distress Medication or condition affecting weight/appetite

2

Tell the calculator what “progress” means.

Fat loss, weight loss, muscle gain and performance are related, but they are not interchangeable goals.

Primary goal

Fat lossPrioritize fat reduction and lean-mass retention, not merely a lower scale number RecompositionBuild or retain muscle while gradually reducing fat MaintainSupport health, energy and weight stability Muscle gainFuel progressive resistance training with a modest surplus PerformanceProtect training fuel, recovery and repeatable output

Energy adjustment Choose a goal first A conservative starting adjustment is usually easier to evaluate and sustain than an aggressive one.

Protein reference weight Current body weight Goal/reference weight entered above Using goal weight can prevent current body weight from producing an impractically high target. It is a planning choice, not medical nutrition therapy.

Protein approach

Evidence-based starting pointGoal-specific target informed by NASM and sports-nutrition research High-protein illustration1 gram per pound of the selected reference weight Custom targetEnter your own grams per pound with clinician/RD guidance

Carbohydrate/fat emphasis

Balanced start30% of calories from fat; carbohydrates fill the remainder Performance / higher carb25% fat; more remaining energy available for carbohydrate Lower-carb preference35% fat; carbohydrates still remain part of the plan

Macro counting is optional. NASM’s current coaching guidance emphasizes that some people benefit from numerical targets, while others do better with hand portions, plate composition and less tracking. If numbers intensify rigidity, guilt or food anxiety, the “more disciplined” move may be to stop tracking and seek qualified support (NASM, 2026b).

3

Calculate the friction, not only the food.

A plan can be physiologically sound and behaviorally impossible. Select what usually breaks first.

My most common obstacles

Persistent hunger or cravings Stress or emotional eating All-or-nothing thinking Time or inconsistent schedule ADHD or executive-function friction Sleep loss or fatigue Takeout or restaurant meals Weekends or social events Budget or food access Cooking confidence Inconsistent resistance training Body image or scale fixation

What else usually makes the plan fall apart?

The Wholeminds distinction: knowing what to do and being able to repeat it are different psychological tasks. Capability, opportunity and motivation all shape behavior; adding more information cannot fix a barrier that is actually emotional, environmental or executive (Michie et al., 2011).

4

Turn the estimate into groceries you would actually eat.

These optional fields populate your final copy-and-paste AI prompt. Leave anything blank and the prompt will ask your assistant to clarify it.

Stores I shop at

Town, state or ZIP

Favorite foods, cuisines and cravings

Dislikes or foods to avoid

Dietary pattern No specific pattern Halal Pescatarian Vegetarian Vegan / fully plant-based Kosher Other / mixed

Allergies, intolerances or other food restrictions

Meal, budget and automation preferences

Maximum active prep time 5 minutes10 minutes15 minutes20 minutes30 minutes

Maximum main ingredients 35710

Servings per recipe

Approximate weekly grocery budget

Meals to generate 5 meals7 meals10 meals14 meals

Available equipment

Weekly sale-check day MondayTuesdayWednesdayThursdayFridaySaturdaySunday

Preferred local time

Automation instruction Ask my AI to create itGive me a reusable weekly prompt only

Other things my AI should know

Privacy before convenience: review the generated prompt before pasting it anywhere. Remove medical, location or personal details you do not want to share. An AI-generated grocery plan can be useful, but it cannot verify food-allergy safety, diagnose a condition or replace individualized medical nutrition care.

Calculate My Energy, Macros & Real-Life Plan →

One tool · four disciplines

The number is only the beginning.

This calculator integrates general education from metabolism, exercise science, nutrition coaching and behavior change.

• BMR/TDEE: the physiological estimate
• Macros: the goal-specific allocation
• TEF: what protein changes at equal calories
• Behavior: why a correct target may still fail
• AI prompt: how the information becomes a usable week

Evidence before spectacle

References

1. Hall, K. D., & Chow, C. C. (2013). Why is the 3500 kcal per pound weight loss rule wrong? International Journal of Obesity, 37(12), 1614. https://doi.org/10.1038/ijo.2013.112
2. Jäger, R., Kerksick, C. M., Campbell, B. I., Cribb, P. J., Wells, S. D., Skwiat, T. M., Purpura, M., Ziegenfuss, T. N., Ferrando, A. A., Arent, S. M., Smith-Ryan, A. E., Stout, J. R., Arciero, P. J., Ormsbee, M. J., Taylor, L. W., Wilborn, C. D., Kalman, D. S., Kreider, R. B., Willoughby, D. S., … Antonio, J. (2017). International Society of Sports Nutrition position stand: Protein and exercise. Journal of the International Society of Sports Nutrition, 14, 20. https://doi.org/10.1186/s12970-017-0177-8
3. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. (2024). KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney International, 105(4S), S117-S314. Guideline PDF
4. Michie, S., van Stralen, M. M., & West, R. (2011). The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implementation Science, 6, 42. https://doi.org/10.1186/1748-5908-6-42
5. Mifflin, M. D., St Jeor, S. T., Hill, L. A., Scott, B. J., Daugherty, S. A., & Koh, Y. O. (1990). A new predictive equation for resting energy expenditure in healthy individuals. The American Journal of Clinical Nutrition, 51(2), 241-247. https://doi.org/10.1093/ajcn/51.2.241
6. Morton, R. W., Murphy, K. T., McKellar, S. R., Schoenfeld, B. J., Henselmans, M., Helms, E., Aragon, A. A., Devries, M. C., Banfield, L., Krieger, J. W., & Phillips, S. M. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 52(6), 376-384. https://doi.org/10.1136/bjsports-2017-097608
7. National Academy of Sports Medicine. (2026a). Calorie calculator: How to calculate BMR, TDEE, and macronutrients. https://www.nasm.org/resources/calorie-calculator
8. National Academy of Sports Medicine. (2026b, August 20). The weightlifting diet: How trainers coach nutrition for strength. https://www.nasm.org/resource-center/blog/nutrition/how-to-count-macros
9. National Academy of Sports Medicine. (2026c). How much protein should you eat per day to support weight loss? NASM resource
10. Westerterp, K. R. (2004). Diet induced thermogenesis. Nutrition & Metabolism, 1, 5. https://doi.org/10.1186/1743-7075-1-5
11. Wishnofsky, M. (1958). Caloric equivalents of gained or lost weight. The American Journal of Clinical Nutrition, 6(5), 542-546. https://doi.org/10.1093/ajcn/6.5.542

Doing therapy, not merely going to therapy

A calculator can estimate the target. It cannot understand what keeps happening between you and the target.

Wholeminds Wellness integrates psychology, exercise science, nutrition and behavior change through practical online psychotherapy for adults throughout New Jersey.

Book a Free 15 Minute Call → Check Insurance Cost →

Insurance applies to eligible psychotherapy services. Fitness and nutrition expertise may inform psychotherapy but is not billed as a separate fitness, nutrition or medical service. Coverage varies by plan.