Kalkulator BMR
Your basal metabolic rate (BMR) represents the minimum amount of energy your body needs to sustain vital functions at complete rest – breathing, circulating blood, controlling body temperature, and repairing cells. A reliable kalkulator BMR gives you that baseline calorie number, which is the first step toward any science‑based nutrition or fitness plan. Whether your goal is weight loss, muscle gain, or simply understanding your metabolism better, knowing your BMR removes the guesswork.
How the kalkulator BMR estimates your resting energy burn
The calculator above uses the Mifflin‑St Jeor equation, recognized as the most accurate formula for predicting resting energy expenditure in the general population. It takes four personal inputs: age, sex, weight, and height. With those numbers it computes the calories you would burn if you stayed in bed all day.
Once you have your BMR, you can turn it into a practical daily calorie target. Simply multiply the result by an activity factor that matches your lifestyle:
| Activity level | Description | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise | 1.2 |
| Lightly active | Light exercise 1–3 days/week | 1.375 |
| Moderately active | Moderate exercise 3–5 days/week | 1.55 |
| Very active | Hard exercise 6–7 days/week | 1.725 |
| Extra active | Very hard daily training or physical job | 1.9 |
The product is your total daily energy expenditure (TDEE) – the full picture of how many calories you burn in a day.
What is the Mifflin‑St Jeor equation and why is it trusted?
The Mifflin‑St Jeor equation was developed in 1990 and validated against indirect calorimetry in a large sample of overweight and normal‑weight individuals. Two versions exist:
- Male: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
- Female: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
For example, a 35‑year‑old woman who weighs 68 kg and is 165 cm tall would have a BMR of approximately (10×68) + (6.25×165) – (5×35) – 161 = 1,375 kcal/day. That is the energy her body requires at rest – not counting any movement.
Factors that affect your BMR beyond the formula
While age, sex, weight, and height explain most of the variance, several other elements influence your basal metabolic rate:
- Body composition: Muscle tissue burns more calories at rest than fat. Two people of the same weight can have different BMRs if one carries more lean mass.
- Hormones: Thyroid hormones and stress‑related cortisol levels can speed up or slow down metabolism.
- Climate and body temperature: Extreme cold or heat forces the body to expend extra energy to maintain a stable core temperature.
- Crash dieting history: Prolonged very‑low‑calorie intake can lower BMR as an adaptive response.
- Pregnancy and lactation: Both significantly increase energy demands.
The kalkulator BMR provides a solid starting estimate, but if you have unusually high muscle mass or a known metabolic condition, consider it a baseline rather than an absolute.
From BMR to a weight‑loss plan: using the numbers
A sustainable fat loss strategy begins with your TDEE, derived from BMR. Subtract 300–500 calories from that daily figure to create a moderate deficit. For example, a person with a TDEE of 2,300 kcal would aim for around 1,800–2,000 kcal daily to lose roughly 0.25–0.5 kg per week. Avoid dropping below your BMR for extended periods, as that can trigger muscle loss and a metabolic slowdown.
Conversely, if muscle gain is the goal, add 200–300 calories to TDEE and pair it with resistance training. The body needs a slight surplus to build new tissue efficiently.
Frequently Asked Questions
What is BMR and why does it matter?
BMR, or basal metabolic rate, is the number of calories your body burns at complete rest to maintain life‑sustaining functions like breathing and circulation. Knowing your BMR helps you determine exactly how much energy you need to maintain, lose, or gain weight.
How does the kalkulator BMR work?
The kalkulator BMR uses the Mifflin‑St Jeor equation, one of the most accurate formulas for estimating resting energy expenditure. It factors in your age, sex, weight, and height to calculate the minimum calories your body burns daily even without any physical activity.
What is the Mifflin‑St Jeor equation?
The Mifflin‑St Jeor equation is a scientifically validated formula for estimating BMR. For men it is (10 × weight in kg) + (6.25 × height in cm) – (5 × age) + 5. For women it is (10 × weight in kg) + (6.25 × height in cm) – (5 × age) – 161.
How can I use BMR to lose weight?
To lose weight you must consume fewer calories than your total daily energy expenditure (TDEE). First calculate BMR, then multiply it by your activity factor to get TDEE. A moderate deficit of 500 calories below TDEE typically leads to about 0.5 kg of fat loss per week.
Does age affect BMR?
Yes, BMR naturally declines with age because muscle mass tends to decrease and hormonal changes occur. The Mifflin‑St Jeor formula accounts for this by subtracting a value proportional to age; on average, BMR drops by roughly 1–2% per decade after age 20.
This article provides general information and is not a substitute for personalized advice from a doctor or registered dietitian.