Calories, BMI and Macros
BMI, desirable body weight, BMR, total daily energy expenditure and a full macro split — with a choice of Mifflin–St Jeor or the Krause shortcut, and goal-based or percentage macros.
Negative = deficit, positive = surplus. Applied on top of TDEE.
Enter height, weight, and age to calculate.
Formulas
BMI = weight (kg) ÷ height (m)²
DBW (Devine), men = 50 kg + 2.3 kg × (inches over 5 ft)
DBW (Devine), women = 45.5 kg + 2.3 kg × (inches over 5 ft)
BMR (Mifflin–St Jeor), men = 10 × DBW + 6.25 × height(cm) − 5 × age + 5
BMR (Mifflin–St Jeor), women = 10 × DBW + 6.25 × height(cm) − 5 × age − 161
TDEE = BMR × activity factor (1.2 / 1.375 / 1.55 / 1.725 / 1.9)
Krause: TDEE = DBW × kcal/kg for the activity band (midpoints 27.5 / 32.5 / 37.5 / 42.5)
Protein g = DBW × 1.2–2.0; Fat g = DBW × 0.8–1.0; Carbs = remaining kcal ÷ 4
How It Works
Note for students: this calculator applies Mifflin–St Jeor and every per-kg target to desirable body weight rather than scale weight, so a client carrying extra fat does not get calorie and protein targets inflated by it. The textbook form of Mifflin–St Jeor uses actual weight — comparing the two is a good class exercise.
Protein and carbohydrate supply 4 kcal per gram and fat 9, which is how the grams and calories reconcile.
Sources
- Mifflin MD, St Jeor ST, et al. (1990). Am J Clin Nutr 51(2):241–247.
- Devine BJ (1974). Gentamicin therapy. Drug Intell Clin Pharm 8:650–655.
- WHO (2000). Obesity: preventing and managing the global epidemic (BMI categories).
Questions
Which BMR equation does this calorie calculator use?
Mifflin–St Jeor by default, with the Krause kcal-per-kg shortcut as an alternative. It applies the equation to desirable body weight (Devine) rather than actual body weight.
What is the difference between BMR and TDEE?
BMR is the energy used at complete rest. TDEE multiplies it by an activity factor to estimate total daily energy expenditure, which is the number calorie targets are built from.
How are the macros calculated?
In goal-based mode, protein and fat are set in grams per kg of desirable body weight for the chosen goal, and carbohydrate fills the remaining calories. Percentage mode splits the calorie target by the percentages you enter.
From Classroom to Clients
When your students start coaching, TrainerQ runs these same calculations on real clients — with programs, progress reports and bookings in one place. Free for coaches.