Want to understand your body is energy needs? Our BMR & Calorie Calculator estimates your Basal Metabolic Rate (BMR) and daily calorie requirements based on your age, weight, height, and activity level. Perfect for weight management, fitness goals, and healthy living, this tool delivers accurate, personalized insights to fuel your lifestyle.
A BMR calculator & Calorie Calculator determines your Basal Metabolic Rate—the energy your body uses at rest to maintain vital functions like breathing, heart rate, and brain activity. It adjusts for activity to estimate total daily calorie needs, offering:
BMR accounts for ~70% of daily calorie burn, with ~20% from physical activity and ~10% from digestion (thermogenesis). It is measured under strict conditions, requiring a fully rested state with an inactive sympathetic nervous system.
The calculator uses the Mifflin-St Jeor equation to compute BMR, then multiplies by an activity factor (1.2–1.9) to estimate total daily energy expenditure (TDEE).
Example:
Female, 25 years, 65 kg, 165 cm, moderately active
BMR: (10 × 65) + (6.25 × 165) - (5 × 25) - 161 = 1,396 kcal
TDEE (Moderate Activity, 1.6 factor): 1,396 × 1.6 ≈ 2,234 kcal
Mifflin-St Jeor Equation:
Men: BMR = 10W + 6.25H - 5A + 5
Women: BMR = 10W + 6.25H - 5A - 161
Revised Harris-Benedict Equation:
Men: BMR = 13.397W + 4.799H - 5.677A + 88.362
Women: BMR = 9.247W + 3.098H - 4.330A + 447.593
Katch-McArdle Formula:
BMR = 370 + 21.6(1 - F)W
Where: W = weight (kg), H = height (cm), A = age, F = body fat (%)
Instantly get:
✔ Your BMR and daily calorie needs
✔ Tailored recommendations for your goals
✔ Tips for diet and exercise optimization
Q1: How accurate is the BMR calculator?
It uses the Mifflin-St Jeor equation, the most reliable formula, though individual factors may cause slight variations.
Q2: Can it help with weight loss?
Yes, it calculates calorie deficits for safe fat loss.
Q3: Does it account for muscle mass?
The Katch-McArdle formula can be used if you know your body fat percentage.
Q4: Why does age affect BMR?
Older age reduces muscle mass, lowering BMR.
Q5: Can I use imperial units?
Yes, input weight in pounds and height in feet/inches.
Your Basal Metabolic Rate (BMR) is the energy required to sustain vital organs—heart, brain, kidneys, liver, lungs, muscles, and more—while at rest in a neutral environment with no digestive activity. Think of it as the fuel an idling car uses. For most, BMR accounts for ~70% of daily energy, with physical activity (~20%) and digestion (~10%, via thermogenesis) making up the rest.
Accurate BMR measurement demands a fully rested state with an inactive sympathetic nervous system. Online calculators estimate BMR using statistical equations, as precise lab tests (e.g., calorimetry) are less accessible. The Mifflin-St Jeor equation, introduced in 1990, is the most accurate, surpassing the revised Harris-Benedict equation. For lean individuals with known body fat percentages, the Katch-McArdle formula, which factors in lean body mass, may offer greater precision.
BMR and RMR are often confused. RMR (Resting Metabolic Rate) measures energy use in a relaxed but not fully rested state, allowing for less strict conditions. BMR requires total physiological equilibrium, making it harder to measure accurately outside labs.
A 2005 study* found a 26% unexplained variance in BMR even after controlling for factors like fat-free mass and age. This means calculations, even with precise methods, are estimates. For best results, combine BMR/TDEE estimates with a journal tracking exercise, diet, and progress to identify what works for your body.
* Johnstone AM, Murison SD, Duncan JS, Rance KA, Speakman JR, Factors influencing variation in basal metabolic rate include fat-free mass, fat mass, age, and circulating thyroxine but not sex, circulating leptin, or triiodothyronine. Am J Clin Nutr 2005; 82: 941-948.
Our BMR Calculator comes with detailed guides, documentation, and step-by-step instructions to help you calculate your Basal Metabolic Rate easily. This section also includes a comprehensive FAQ to answer common questions about using the BMR Calculator and understanding your daily calorie needs.
A BMR Calculator estimates your Basal Metabolic Rate — the number of calories your body needs to perform basic life functions like breathing, circulation, and cell production while at rest. It is the foundation for understanding your daily calorie needs.
Our BMR Calculator uses the Mifflin-St Jeor equation, one of the most accurate formulas for calculating BMR. You just need to enter your age, gender, height, and weight. The calculator then estimates the calories your body burns at rest, which can be adjusted based on your activity level.
Knowing your BMR is the first step in creating aweight management plan. To lose weight, you need to consume fewer calories than your calorie needs. To gain weight, you must eat more than your BMR plus activity level. The BMR Calculator helps you set realistic fitness and diet goals.
Yes, our BMR Calculator is completely free and available online. You do not need an account or subscription to calculate your daily calorie needs.
The BMR Calculator uses a widely accepted scientific formula. While results are highly accurate for most people, keep in mind that factors like muscle mass, body composition, and metabolism can influence your exact calorie needs. For precise health or diet plans, consult a nutritionist.
Absolutely! The BMR Calculator 2025 is updated with the latest formulas and is ideal for people planning weight loss, muscle gain, or maintenance. You can combine it with calorie trackers or diet plans to get the best results.
BMR (Basal Metabolic Rate) is the energy your body burns at rest, while TDEE (Total Daily Energy Expenditure)includes all activities like exercise, work, and daily movement. OurBMR Calculator gives you the baseline, and you can then adjust based on your activity level to get your exact calorie needs.
Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic functions like breathing, circulation, and cell production while at complete rest.
Formula (Mifflin-St Jeor):
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