About MaintenanceCalorie
Democratizing evidence-based metabolic science through speed, radical privacy, and clinical rigor.
Our Mission
Understanding your daily energy balance should not require navigating a maze of popup ads, multi-step email harvest funnels, or proprietary black-box algorithms. We built MaintenanceCalorie to provide athletes, coaches, and health-conscious individuals with a direct, accurate, and blazing-fast baseline of their Total Daily Energy Expenditure (TDEE).
“Most online fitness calculators exist to harvest marketing leads and sell detox teas. We built MaintenanceCalorie to provide transparent, uncompromised metabolic math.”
Every formula, activity multiplier, and macronutrient recommendation on this platform is taken directly from peer-reviewed clinical nutrition literature. We provide the mathematical tools and explain the underlying physiology so you can make informed decisions about your nutrition.
Core Principles
1. Clinical Rigor & Empirical Evidence
We strictly reject pseudoscience, “starvation mode” fallacies, and unsubstantiated metabolic claims. Our calculators use standard clinical equations—including the Mifflin-St Jeor, Katch-McArdle, and revised Harris-Benedict formulas—which have been repeatedly validated in human trials.
2. Privacy by Design
Your body weight, height, age, and body fat percentage are sensitive personal metrics. All calculations execute locally inside your web browser using client-side JavaScript. We do not store your metrics on our servers, nor do we sell or monetize your data.
3. Minimalist, Frictionless Usability
We respect your attention. No interstitial banners, no autoplay videos, and no paywalled features. Calculations update in real time as you adjust values, giving you immediate feedback without friction.
Clinical Equations
Different bodies and data sets require different mathematical models. We support the primary clinical formulas used in sports nutrition and clinical dietetics:
| Formula | Required Inputs | Best Suited For |
|---|---|---|
| Mifflin-St Jeor (1990) | Sex, Age, Height, Weight | General adult population; endorsed by the Academy of Nutrition and Dietetics. |
| Katch-McArdle (1996) | Lean Body Mass (LBM) / Body Fat % | Athletes, bodybuilders, and anyone with a reliable body fat measurement. |
| Revised Harris-Benedict (1984) | Sex, Age, Height, Weight | Historical clinical comparisons and cross-validation against earlier data sets. |
For baseline calculations without known body fat, the Mifflin-St Jeor equation is our recommended standard. Multiple systematic reviews have demonstrated that it predicts resting metabolic rate within 10% of indirect calorimetry in non-obese and obese individuals more consistently than other weight-based equations.
Mathematical Formulations
Mifflin-St Jeor Equation (1990)
- For biological males:
BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5 - For biological females:
BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161
Katch-McArdle Formula (1996)
Driven strictly by Lean Body Mass (LBM):
BMR = 370 + (21.6 × LBM in kg)
Where lean body mass is derived from biological body fat percentage:
LBM = weight in kg × (1 - (Body Fat % / 100))
Total Daily Energy Expenditure (TDEE)
Total expenditure scales your basal rate by the physical activity level multiplier (PAL):
TDEE = BMR × PAL
Biologically, this represents the sum of all daily energy compartments:
TDEE = BMR + NEAT + TEF + EAT
Components of Daily Energy Expenditure
Your Total Daily Energy Expenditure is the cumulative sum of four distinct metabolic components:
- Basal Metabolic Rate (BMR) ~60–70%: The energy required to sustain life at complete physical and digestive rest, powering vital functions such as respiration, circulation, and cellular repair.
- Non-Exercise Activity Thermogenesis (NEAT) ~15–20%: Energy expended through spontaneous daily movement such as walking, posture maintenance, typing, and chores. NEAT is typically the most variable component between individuals.
- Thermic Effect of Food (TEF) ~8–10%: The metabolic cost of digesting, absorbing, and assimilating nutrients. Protein possesses the highest thermic cost (20–30%), followed by carbohydrates (5–10%) and dietary fats (0–3%).
- Exercise Activity Thermogenesis (EAT) ~5–10%: Energy burned during intentional, structured workouts (resistance training, running, swimming). While intense, it generally represents a smaller portion of daily energy than NEAT.
Adaptive Calibration
No mathematical formula can account for individual hormonal status, gut microbiome variance, or subtle changes in spontaneous activity. Calculated maintenance calories should always be treated as a starting hypothesis.
To establish your true empirical maintenance level:
- Consume your calculated maintenance calories consistently for 14 to 21 days.
- Weigh yourself daily each morning under identical conditions (fasted, after using the restroom).
- Calculate weekly rolling averages to filter out transient water weight fluctuations.
- If your weekly average is stable, your intake matches your actual maintenance. If average weight is drifting up or down, adjust your intake by 100–150 kcal and re-evaluate.
Scientific Citations
- 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.
- Katch, F. I., & McArdle, W. D. (1996). Nutrition, Weight Control, and Exercise. Lea & Febiger.
- Roza, A. M., & Shizgal, H. M. (1984). The Harris Benedict equation reevaluated: resting energy requirements and the mass variable. The American Journal of Clinical Nutrition, 40(1), 168-182.
- Frankenfield, D., Roth-Yousey, L., & Compher, C. (2005). Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association, 105(5), 775-789.