About Health Estimates
These numbers are designed to help you understand your training and nutrition at a glance. They are informational only and not a substitute for professional medical advice, diagnosis, or treatment.
Last updated: October 28, 2025 • Version: v1.0
What We Show
BMI — A population screening measure based on height and weight.
Estimated Daily Calories — An estimate of maintenance energy needs using the Mifflin–St Jeor equation and your selected activity level.
We label these as estimates because they can vary with factors like genetics, metabolism, and device/measuring error.
BMI
What it is
Body Mass Index (BMI) is a simple ratio of weight to height used as a screening tool for potential weight categories. It does not measure body fat directly or diagnose health.
Formula
Metric: BMI = weight(kg) ÷ [height(m)]²
U.S.: BMI = 703 × weight(lb) ÷ [height(in)]²
Units & Conversions
1 inch = 2.54 cm
1 lb = 0.453592 kg
height(m) = height(cm) ÷ 100
Limitations
Does not distinguish between fat and lean mass (e.g., athletes may have a high BMI but low body fat).
Can be less accurate for older adults and certain populations.
Should be considered alongside other measures (waist circumference, body composition, labs, clinical assessment).
Primary Sources
CDC — About Adult BMI: https://www.cdc.gov/bmi/about/index.html
CDC — BMI Categories: https://www.cdc.gov/bmi/adult-calculator/bmi-categories.html
Estimated Daily Calories (Maintenance)
What it is
Your estimated maintenance calories are the energy (kcal) needed per day to maintain current body weight, assuming your stated activity level.
How we estimate
We calculate Resting Energy Expenditure (REE) using the Mifflin–St Jeor equation.
We multiply REE by an activity factor to reflect daily movement and exercise.
Mifflin–St Jeor REE (kcal/day)
Male: REE = 10 × weight(kg) + 6.25 × height(cm) – 5 × age(years) + 5
Female: REE = 10 × weight(kg) + 6.25 × height(cm) – 5 × age(years) – 161
Activity Factors (guide)
Sedentary (little or no exercise): × 1.2
Lightly active (1–3 days/week): × 1.375
Moderately active (3–5 days/week): × 1.55
Very active (6–7 days/week): × 1.725
Extra active (hard exercise + physical job): × 1.9
Assumptions & Notes
Equations are based on population averages; individual needs can differ.
Activity multipliers are adapted from public health guidance; choose the level that best reflects your routine.
If your weight trends up or down over time, adjust calories or activity level accordingly.
Primary Sources
Mifflin MD, St Jeor ST, et al. "A new predictive equation for resting energy expenditure in healthy individuals." American Journal of Clinical Nutrition (1990). DOI: 10.1093/ajcn/51.2.241
(PubMed: https://pubmed.ncbi.nlm.nih.gov/2305711/)U.S. Department of Health and Human Services — Physical Activity Guidelines: https://health.gov/paguidelines
How We Handle Numbers
Rounding: We round calorie estimates to the nearest whole number and BMI to one decimal.
Units: You can switch between imperial and metric in Settings.
Data quality: Small input errors (e.g., height entered in inches vs. cm) can produce large differences. Please double-check entries.
Important Disclaimers
These metrics are screening and estimation tools only. They do not diagnose health conditions.
For personalized guidance, consult a qualified healthcare professional or registered dietitian.
If you have a medical condition, are pregnant, breastfeeding, or under 18, please seek professional advice before acting on these estimates.
Additional References
Dietary Guidelines for Americans, 2020–2025: https://www.dietaryguidelines.gov
CDC — Healthy Weight, Nutrition, and Physical Activity: https://www.cdc.gov/healthyweight
Feedback
If something looks off or you have suggestions, email us at support@sculptai.io. We review this page regularly and update sources, formulas, and language as needed.
Last updated: January 3, 2026
