BMR Calculator: Basal Metabolic Rate or BMR is the total calories required to by your body at rest, to function normally.
BMR is also an indication of the body’s metabolism. Hence, an increase in metabolic weight will directly result in increased BMR. Our body burns calorie while performing the most basic life-sustaining activities like breathing, cell production, blood circulations with the help of the various organs.
The basal metabolic rate is slightly different from the resting metabolic rate (RMR). While both are a measure of the total calories your body burns at rest, RMR is measured before breakfast or exercise in the morning and after a night’s restful sleep. Your RMR is an accurate estimate of your BMR. Both the terms are used by experts and nutritionists to describe the same factor.
How to Calculate Basal Metabolic Rate With BMR Calculator?
To calculate your BMR, you can either use the formula formulated by scientists, or you can use an online BMR calculator.
Neither a basal metabolic rate calculator or the use of formula gives an accurate measure of your BMR, although a lab test result gives a more accurate estimate.
Pro Tip: – You can also check out our TDEE Calculator to calculate your Total Daily Energy Expenditure.
The Harris-Benedict Equation used to estimate basal metabolic rate is:
- For Men: BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)
- For Women: BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)
The BMR is calculated under restrictive circumstances while a person is awake. An accurate BMR measurement requires a person’s sympathetic nervous system to be inactive. So a person must take complete rest.
BMR is the most significant component of your total caloric needs. The caloric needs daily, is the BMR value multiplied by a factor whose value is between 1.2 and 1.9, depending on your activity levels.
The most commonly used equation which BMR Calculator mostly use is the Mifflin- St Jeor equation:
• For men, BMR = 10 × weight(kg) + 6.25 × height(cm) – 5 × age(y) + 5
• For women, BMR = 10 × weight(kg) + 6.25 × height(cm) – 5 × age(y) – 161
Factors Affecting BMR
The BMR variables are which affects the result of a BMR Calculator are:
• Muscle Mass– Aerobic exercises like cycling or running, does not affect BMR, but anaerobic exercises, like weight-lifting, indirectly leads to an increased BMR. It builds muscle mass, increasing the resting energy consumption. More the muscle mass in the body composition of a person, the higher he needs the BMR to maintain his body.
• Age– The older and thinner an individual, the lower is their BMR or the minimum requirement of caloric intake to sustain the functioning of their organs at a particular level is lower.
• Genetics– All the hereditary traits passed down from ancestors to an individual, influence his BMR.
• Weather– BMR increases under cold environments because energy is needed to create a homeostatic body temperature. Similarly, external heat can increase BMR when the body loses energy to cool off the internal organs.
• Diet– Small and timely distributed meals increase BMR. Starvation can lead to reducing BMR by 30%.
• Pregnancy– Pregnancy leads to an increased BMR. The fetus inside the womb needs to be fed too. This is the reason pregnant women tend to eat a lot. Menopause can increase or decrease the BMR depending on hormonal changes.
• Supplements– There are certain supplements or drugs which can affect the BMR. Their use shows an increased result on the basal metabolic rate calculator. These supplements help in weight loss. Caffeine is a common example.
Online Basal Metabolic Rate Calculator
Online basal metabolic rate calculator requires you to enter your age, gender, weight, and height along with your daily activity levels. The result indicates an estimate of the total number of calories you burnt in a day.
A combination of factors governs your BMR. Age, gender, genetic factors, body composition, all play an essential role in determining your result of the basal metabolic rate calculator.
There is nothing you can do about genetic factors, age, and gender, but you can control your body composition to determine your BMR and boost your metabolism.
When you build muscle, even at rest, your body burns calorie from lean muscle mass and not your fat. Resistance training causes a 7-8% increase in RMR.
Once you have got the result from BMR calculator, you know how many calories your body burns in a day. You can use these data, to lose weight.
Your BMR and two other factors determine the total number of calories burnt by your body daily:
- BMR- 60-70% of calories burnt daily.
- Activity thermogenesis (non-exercise movement and exercise) – 15-30% calories burnt daily from the total calories burn.
- Thermic effect of food (calories burned from eating and digestion)- 10% of the total calories burnt daily.
When you burn more calories than your intake in a day, your body creates a calorie deficit. Such daily deficits of 500-1000 calories daily can result in weight loss of 1-2 pounds in a week.
Knowing the number of calories you burnt in a day from the BMR calculator, is a step in maintaining a healthy weight and diet. Your BMR is an indication of how many calories you need to intake to balance your weight. Hence, it helps you decide your diet.
Use a basal metabolic rate calculator once every week, to keep tracks of your BMR and any noticeable changes.