BMR Calculator
Discover how many calories your body burns at rest. Essential data for effective weight loss, muscle gain, or maintenance.
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Average Basal Metabolic Rate by Age & Gender
Reference values for daily Basal Metabolic Rate (kcal/day) based on general population averages (Japan Ministry of Health, Labour and Welfare data for reference). Use this as a guideline to see how your calculated BMR compares to the average.
| Age | Male | Female |
|---|---|---|
| 18-29 | 1,520 kcal/day | 1,110 kcal/day |
| 30-49 | 1,530 kcal/day | 1,150 kcal/day |
| 50-64 | 1,480 kcal/day | 1,110 kcal/day |
| 65-74 | 1,400 kcal/day | 1,080 kcal/day |
| 75+ | 1,280 kcal/day | 1,010 kcal/day |
Formulas
Harris-Benedict Equation (Revised)
Male: BMR = 88.362 + (13.397 × weight kg) + (4.799 × height cm) - (5.677 × age)
Female: BMR = 447.593 + (9.247 × weight kg) + (3.098 × height cm) - (4.330 × age)
The Harris-Benedict equation is a formula originally published in 1919 and revised by Roza and Shizgal in 1984. It estimates your basal metabolic rate (BMR) based on your weight, height, age, and gender. Because it provides a highly accurate estimate for most people, it remains the most widely used formula in medical and fitness fields worldwide.
How to Use
- STEP 1
- Select gender, enter age, height, and weight, then press 'Calculate BMR' button for automatic calculation.
- STEP 2
- The result shows daily basal metabolic rate (kcal) and the formula used.
- STEP 3
- Use as reference for diet, health management, and nutrition planning.
Notes
- BMR is the minimum energy expenditure required for vital functions at rest (e.g., during sleep).
- Actual daily calorie expenditure is higher than this value depending on activity level.
- Individual factors like muscle mass, body fat percentage, body temperature, and hormonal balance are not considered.
- May not apply to pregnant/nursing women, growing children, or those recovering from illness.
- This tool is for health management reference and does not replace medical diagnosis or nutritional guidance.
Tips
BMR is the energy required for vital functions like heartbeat, breathing and temperature regulation; it makes up about 60–70% of daily energy expenditure.
To increase BMR, focus on resistance training, HIIT, adequate sleep (7–9 hours), sufficient protein intake (approx. 1.2–1.6 g/kg), and staying well hydrated.
BMR changes with age: it tends to peak in youth and gradually declines due to loss of muscle mass and reduced cellular activity.
Men generally have higher BMR because of greater muscle mass and bone density; hormonal differences also contribute.
Organs contribute differently to BMR (e.g., liver ~27%, brain ~19%, muscle ~18%), so increasing muscle mass is an effective way to raise metabolism.
Diet-induced thermogenesis (e.g., protein-rich meals) can temporarily raise metabolic rate.
Rapid or extreme dieting can lower BMR and cause muscle loss; aim for gradual, sustainable changes.
Use BMR as a baseline only—total daily needs depend on activity level and lifestyle.
FAQ
Q1
Difference between BMR and total daily energy expenditure?
BMR is energy consumption at rest, while Total Daily Energy Expenditure (TDEE) includes daily activities. TDEE = BMR × activity factor (1.2-1.9).
Q2
How to use BMR for dieting?
Intake below BMR causes muscle loss and metabolic decline. Maintain calorie intake above BMR×1.2 and increase calorie expenditure through exercise for healthy weight loss.
Q3
How accurate is the Harris-Benedict equation?
For standard body types, accuracy is within ±10%. Accuracy may decrease for individuals with extremely high/low muscle mass or body fat percentage.
Q4
What happens with a low BMR?
Symptoms may include fatigue, cold sensitivity, constipation, poor concentration, and a tendency to gain weight easily. It can make weight loss more difficult.
Q5
How can I set calories for muscle gain?
Aim for a surplus of 300–500 kcal over your Maintenance Calories (TDEE) and ensure sufficient protein intake (approx. 1.6–2.2 g/kg).
Q6
How can I break through a weight loss plateau?
Try a diet break or 'cheat day' to stimulate metabolism, or change your exercise routine to provide a new stimulus. Avoid extreme restriction below BMR.
Q7
Does muscle mass affect BMR?
Yes. Each kg of muscle increases BMR by about 13 kcal/day. Resistance training is key to raising your baseline metabolism.
Q8
Should I eat below BMR to lose weight?
No. Eating below BMR for long periods risks muscle loss and metabolic slowdown. Aim for a moderate deficit based on your total daily energy expenditure (TDEE).
Q9
What is the breakdown of BMR energy consumption?
BMR is distributed among organs: liver (~27%), brain (~19%), skeletal muscle (~18%), kidneys (~10%), heart (~7%), and others (~19%). This highlights why muscle mass is key to boosting metabolism.
Q10
How accurate is the Harris-Benedict equation?
For standard body types, accuracy is within ±10%. However, it may be less accurate for individuals with extremely high muscle mass or high body fat percentages.
Q11
What happens if my BMR is low?
Symptoms of low BMR may include constant fatigue, sensitivity to cold, constipation, poor concentration, and a tendency to gain weight easily even with low intake.
Q12
Can my diet change my BMR?
Extreme caloric restriction can lower BMR by up to 20% as a survival mechanism. Conversely, the thermic effect of food, especially protein, can temporarily boost metabolic rate.