BMR and TDEE
BMR estimates energy use at rest. TDEE adds an activity factor. The activity factor is often the least precise input because real daily movement varies.
Calories and goals
Calorie calculators may estimate maintenance, weight-loss or weight-gain targets. Safer pages should explain that aggressive targets may be inappropriate and that individual needs vary.
Macros and protein
Macro and protein calculators distribute calories across protein, fat and carbohydrate. Results depend on body size, activity, goals and dietary constraints.
Common mistakes
- Treating a formula estimate as a precise personal requirement.
- Overstating activity level.
- Ignoring changes in body weight, training and adherence over time.
- Using calculator output for medical diets without professional guidance.
Useful calculators
FAQ
Why is TDEE only an estimate?
Activity level, non-exercise movement, body composition and tracking accuracy vary from person to person.
Which BMR formula is best?
No formula is perfect. Mifflin-St Jeor is commonly used for adult estimates, but individual error remains.
Can this replace a dietitian?
No. It is general calculation support, not personalized nutrition care.
Named formulas and entities
BMR, TDEE, MET, protein target, macro split and target heart rate are different estimates. Mifflin-St Jeor estimates resting energy needs, while TDEE multiplies BMR by an activity factor.
Concrete scenario
If BMR is 1,600 kcal/day and the selected activity factor is 1.55, estimated TDEE is 2,480 kcal/day. If the true activity level is closer to 1.35, the estimate drops to 2,160 kcal/day.
Health caveats
Do not use calculator targets for eating disorder recovery, pregnancy, illness, pediatric nutrition or medical diets without qualified care.
Activity factors are broad categories.
Observed weight trend and energy level matter more than a single formula output.
Last reviewed: 2026-05-14.