Worked examples, in Fat Loss
BMR Examples
Your BMR is the number of calories your body burns simply to exist, powering vital functions like breathing, circulation, and cell production. While it's a metric, it's not your total daily calorie burn. By calculating BMR in various real-world scenarios, we can better understand how different factors influence this baseline and how to strategically approach fat loss.
4 examples. Published Mar 12, 2026. Updated Mar 27, 2026. By AI Fit Hub.
Worked examples
See the inputs and outcome together
Each scenario keeps the starting point, the outcome, and the actual lesson in one place so the page reads like a decision notebook, not a data dump.
- 1
Baseline male, moderate activity
A 30-year-old man, 78 kg and 178 cm, who trains moderately a few times a week.
BMR is 1,748 calories, and maintenance lands at 2,709 once moderate activity is applied.
Sex
Male
Age
30
Weight Kg
78
Height Cm
178
Activity Level
Moderate
BMR is only what your body burns at rest. The jump to 2,709 maintenance comes entirely from the activity multiplier, so picking the right activity level matters far more than the BMR figure itself.
- 2
Same man, athlete activity
Identical stats, but training hard most days as a competitive athlete.
BMR is unchanged at 1,748, but maintenance climbs to 3,320 calories.
Sex
Male
Age
30
Weight Kg
78
Height Cm
178
Activity Level
Athlete
Same body, over 600 extra maintenance calories purely from activity. Most people overestimate this multiplier, then wonder why a generous calorie target stalls their progress. Be honest about how active you really are.
- 3
Female reference
A 30-year-old woman, 65 kg and 165 cm, training moderately.
BMR is 1,370 calories, with maintenance at 2,124.
Sex
Female
Age
30
Weight Kg
65
Height Cm
165
Activity Level
Moderate
The Mifflin-St Jeor equation applies a lower constant for women, which combined with smaller average size yields a lower BMR. Borrowing a male partner's calorie target is a common way to overeat by several hundred calories a day.
- 4
Older male
The same 78 kg, 178 cm man at 55 years old, still moderately active.
BMR falls to 1,623 calories and maintenance to 2,515.
Sex
Male
Age
55
Weight Kg
78
Height Cm
178
Activity Level
Moderate
Twenty-five years trims roughly 200 maintenance calories at the same weight and activity. The equation assumes a gradual metabolic slowdown, which is why eating exactly as you did at 30 slowly adds weight.
Patterns
Run the numbers next
- Planning Calorie Deficit Calculator
Estimate required daily calorie deficit for a target timeline and bodyweight change.
- Nutrition TDEE Calculator
Estimate your daily energy expenditure with Mifflin-St Jeor + activity factors.
Sources
- A new predictive equation for resting energy expenditure in healthy individuals. , American Journal of Clinical Nutrition
- Best practice methods to apply to measurement of resting metabolic rate in adults: a systematic review , Journal of the American Dietetic Association (2006) — Compher et al.
Keep the topic connected
- Formula BMR Formula (Mifflin-St Jeor)
BMR = 10·mass_kg + 6.25·height_cm − 5·age + sex_constant. Mifflin-St Jeor 1990. Sex constant: +5 male, −161 female. Used as the baseline for TDEE and deficit math.
- Learn What Is TDEE? Total Daily Energy Expenditure Explained
TDEE is the total calories your body burns in 24 hours — BMR + activity + digestion. Learn its 4 components, how to calculate it, and why it's.