UseCalcPro
Home
MathFinanceHealthConstructionAutoPetsGardenCraftsFood & BrewingTools
Blog
  1. Home
  2. Health

BMR Calculator

Calculate your daily calorie burn at rest

Your BMR

1,650 cal/day

TDEE

2,558 cal

Weight Loss

2,058 cal

Weight Gain

3,058 cal

Units

Your BMR

1,650

cal/day

TDEE

2,558

cal/day

Weight Loss

2,058

cal/day

Weight Gain

3,058

cal/day

TDEE by Activity Level

Sedentary (1.2x)1,980 cal
Light (1.375x)2,269 cal
Moderate (1.55x)2,558 cal
Active (1.725x)2,846 cal
Very Active (1.9x)3,135 cal
BMR (base): 1,650 cal/day

Daily Calorie Needs

Maintenance2,558
Weight Loss (-500)2,058
Weight Gain (+500)3,058

Frequently Asked Questions

Q

What is BMR (Basal Metabolic Rate)?

BMR is the number of calories your body burns at complete rest to maintain vital functions - breathing, circulation, cell production, brain activity. It represents 60-70% of daily calorie burn. Example: A 30-year-old man, 5'10", 180 lbs has BMR of ~1,800 calories.

  • BMR = calories to keep you alive at complete rest (coma-level rest)
  • Accounts for 60-70% of total daily calorie expenditure
  • Influenced by: Age, sex, weight, height, muscle mass
  • Higher muscle mass = higher BMR
  • BMR decreases about 1-2% per decade after age 20

Think of BMR as your body's "operating cost" - the energy needed just to exist. Your heart beats 100,000 times daily, you breathe 20,000 times, and trillions of cells divide and repair. All this requires energy, which is your BMR.

Q

How is BMR calculated?

The Mifflin-St Jeor equation (most accurate) calculates BMR using weight, height, age, and sex. Men: BMR = 10×weight(kg) + 6.25×height(cm) - 5×age + 5. Women: BMR = 10×weight(kg) + 6.25×height(cm) - 5×age - 161.

  • Mifflin-St Jeor: Most accurate for typical adults
  • Harris-Benedict: Older, tends to overestimate by 5%
  • Katch-McArdle: Best if you know your body fat percentage
  • All formulas are estimates - actual BMR can vary ±10-15%
FormulaAccuracyBest ForDeveloped
Mifflin-St Jeor±10%Most people (recommended)1990
Harris-Benedict±15%Older formula, still used1919
Katch-McArdle±5%If you know body fat %1970s

Example calculation for 30-year-old man, 180 lbs (82 kg), 5'10" (178 cm): BMR = 10(82) + 6.25(178) - 5(30) + 5 = 820 + 1,112.5 - 150 + 5 = 1,787.5 calories. This is just his resting metabolism - add activity for total daily burn (TDEE).

Q

What is the difference between BMR and TDEE?

BMR is calories burned at complete rest. TDEE (Total Daily Energy Expenditure) is BMR plus all activity calories - exercise, walking, fidgeting, digestion. TDEE = BMR × activity multiplier. Example: BMR 1,800 × 1.55 (moderate activity) = TDEE 2,790.

  • Never eat below your BMR long-term (metabolic damage)
  • TDEE is what you use for diet planning
  • BMR + exercise + daily activity + digestion = TDEE
  • Your TDEE is your "maintenance calories"
MetricWhat It MeasuresExample ValueUse For
BMRResting calorie burn1,800 calMinimum calories needed
TDEETotal daily burn2,790 calMaintenance calories
TDEE - 500Weight loss target2,290 calLose 1 lb/week
Q

How can I increase my BMR?

Build muscle through strength training - muscle burns more calories at rest than fat. Each pound of muscle burns ~6 calories/day at rest vs 2 calories for fat. Other factors: Eat enough protein, don't crash diet, get 7-9 hours sleep, stay hydrated, manage stress.

  • Build muscle: Strength train 2-4x/week - most effective method
  • Eat enough protein: 0.7-1g per pound bodyweight
  • Avoid extreme diets: Crash dieting lowers BMR by 15-30%
  • Sleep 7-9 hours: Poor sleep reduces BMR
  • Stay active: NEAT (daily movement) keeps metabolism active
  • Drink cold water: Minor temporary boost
FactorImpact on BMRHow to Optimize
Muscle mass+50-100 cal/10 lbs muscleStrength training
Sleep deprivation-5-15% BMRSleep 7-9 hours
Crash dieting-15-30% BMRModerate deficit (500 cal)
Caffeine+3-5% temporaryCoffee/tea

The most reliable way to increase BMR is building muscle mass. Each pound of muscle burns about 6 calories per day at rest, while fat burns only 2. Adding 10 pounds of muscle increases BMR by ~40-60 calories daily - modest but meaningful over time.

Q

Why does BMR decrease with age?

BMR decreases 1-2% per decade after age 20 due to: muscle loss (sarcopenia), hormonal changes (lower testosterone/estrogen), decreased physical activity, and cellular changes. A 50-year-old has ~10% lower BMR than at 25. Combat this with strength training and protein.

  • Muscle loss: Average adult loses 3-8% muscle per decade after 30
  • Hormonal changes: Lower testosterone/estrogen reduces metabolism
  • Activity decrease: Less spontaneous movement (NEAT)
  • Prevention: Strength training preserves muscle and BMR
  • Protein needs increase with age: 0.7-1g per pound body weight

The good news: BMR decline isn't inevitable. Studies show active older adults who strength train maintain similar BMR to younger adults. "Use it or lose it" applies strongly to muscle mass and metabolism. Prioritize resistance training and adequate protein as you age.

Q

Is BMR the same as RMR (Resting Metabolic Rate)?

BMR and RMR are similar but measured differently. BMR requires 8+ hours of sleep, 12-hour fast, and complete rest in controlled conditions. RMR is measured under less strict conditions - typically after 15 minutes of rest. RMR is usually 10-20% higher than BMR.

  • For practical purposes, BMR and RMR are often used interchangeably
  • Calculators estimate BMR using formulas, not direct measurement
  • Direct measurement (indirect calorimetry) is most accurate
  • Most people don't need to know the difference
MetricMeasurement ConditionsResultPractical Use
BMR8hr sleep, 12hr fast, complete restLower valueClinical/research
RMR15 min rest, 4hr fast10-20% higherPractical estimates
Calculated BMRFormulas (Mifflin-St Jeor)EstimateDIY calculation

Example Calculations

1BMR for a 30-Year-Old Male (70 kg, 175 cm)

Inputs

GenderMale
Age30
Weight70 kg
Height175 cm
Activity LevelModerate (1.55)

Result

BMR1,649 cal/day
TDEE (Maintenance)2,556 cal/day
Weight Loss (-500 cal)2,056 cal/day
Weight Gain (+500 cal)3,056 cal/day

Using Mifflin-St Jeor: BMR = 10 × 70 + 6.25 × 175 - 5 × 30 + 5 = 700 + 1,093.75 - 150 + 5 = 1,649 cal/day. TDEE = 1,649 × 1.55 = 2,556 cal/day.

2BMR for a 25-Year-Old Female (60 kg, 165 cm)

Inputs

GenderFemale
Age25
Weight60 kg
Height165 cm
Activity LevelLight (1.375)

Result

BMR1,345 cal/day
TDEE (Maintenance)1,850 cal/day
Weight Loss (-500 cal)1,350 cal/day
Weight Gain (+500 cal)2,350 cal/day

Using Mifflin-St Jeor: BMR = 10 × 60 + 6.25 × 165 - 5 × 25 - 161 = 600 + 1,031.25 - 125 - 161 = 1,345 cal/day. TDEE = 1,345.25 × 1.375 = 1,850 cal/day.

Formulas Used

Mifflin-St Jeor (Men)

BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5

The most accurate BMR formula for men, recommended by the Academy of Nutrition and Dietetics.

Where:

weight(kg)= Body weight in kilograms
height(cm)= Height in centimeters
age= Age in years

Mifflin-St Jeor (Women)

BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161

The most accurate BMR formula for women.

Where:

weight(kg)= Body weight in kilograms
height(cm)= Height in centimeters
age= Age in years

TDEE from BMR

TDEE = BMR × Activity Multiplier

Total Daily Energy Expenditure calculated by multiplying BMR by an activity factor (1.2 sedentary to 1.9 very active).

Where:

BMR= Basal Metabolic Rate from the Mifflin-St Jeor equation
Activity Multiplier= Factor based on activity level (1.2, 1.375, 1.55, 1.725, or 1.9)

Understanding Your Basal Metabolic Rate

Your Basal Metabolic Rate (BMR) represents the minimum energy your body needs to function while at complete rest. It accounts for 60-70% of your total daily calorie expenditure and is influenced by age, sex, weight, height, and body composition - especially muscle mass.

The Mifflin-St Jeor equation, developed in 1990, is widely considered the most accurate method for estimating BMR. It calculates differently for men and women, accounting for physiological differences in metabolism and body composition.

Knowing your BMR helps with weight management. To lose weight, you need a calorie deficit below your TDEE (BMR × activity level). To gain muscle, you need a surplus. Never eat below your BMR long-term - this can cause metabolic adaptation and muscle loss.

Related Calculators

TDEE Calculator

Total daily energy

Calorie Calculator

Daily calorie needs

BMI Calculator

Body mass index

Macro Calculator

Protein, carbs, fat

Body Fat Calculator

Body composition

Ideal Weight

Target weight range

Related Resources

BMR Explained: Understanding Your Basal Metabolic Rate

Read our guide

TDEE Calculator: How to Calculate Your Total Daily Energy Expenditure

Read our guide

Calories Burned Calculator: How Many Calories Does Exercise Burn?

Read our guide

BMI Calculator

Calculate your body mass index

Calorie Calculator

Find your daily calorie needs

TDEE Calculator

Calculate total daily energy expenditure

More Health Calculators

Tools for nutrition and fitness

View All Health

Last Updated: Mar 9, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

UseCalcPro
FinanceHealthMath

© 2026 UseCalcPro