BMI & Calorie Calculator
Calculate your Body Mass Index and daily calorie needs. Uses the Mifflin-St Jeor formula for accurate TDEE estimates with activity level, goal and macro breakdown.
Healthy weight range for your height: 56.7–76.3 kg
BMI Categories
Underweight
< 18.5
Normal weight
18.5 – 24.9
Overweight
25 – 29.9
Obese
≥ 30
About BMI & Calorie Calculator
Body Mass Index (BMI) is one of the most widely used screening metrics in health and fitness. It provides a quick snapshot of whether your current weight is proportionate to your height, categorizing the result as underweight, normal, overweight, or obese. While BMI has limitations — it does not distinguish between muscle and fat, and may be less accurate for athletes or older adults — it remains a valuable starting point for assessing general health risk and tracking weight changes over time.
Our BMI & Calorie Calculator goes beyond a basic BMI score. The Calorie tab uses the Mifflin-St Jeor equation, the gold standard formula endorsed by dietitians and health organizations worldwide, to estimate your Total Daily Energy Expenditure (TDEE). This accounts for your age, sex, height, weight, and physical activity level to produce a personalized caloric target. From there, the calculator breaks down maintenance calories alongside deficit and surplus targets for weight loss or muscle gain, and suggests macro ratios for protein, carbohydrates, and fat.
All calculations run instantly in your browser. No data is sent to a server, and no account is required. Whether you are starting a fitness journey, tracking progress, or just curious, this tool gives you meaningful numbers to work with in seconds.
How to Use BMI & Calorie Calculator
- 1Select the BMI tab and enter your height and weight in your preferred unit system (metric or imperial).
- 2Review your BMI score and the healthy weight range displayed for your height.
- 3Switch to the Calorie tab and enter your age, biological sex, and activity level.
- 4Read your TDEE (maintenance calories) and the weight-loss or weight-gain targets calculated for you.
- 5Use the macro breakdown as a starting guide for structuring your daily protein, carb, and fat intake.
Use Cases
- →Check if your current weight falls within a healthy BMI range for your height
- →Calculate how many calories you need daily to lose, maintain, or gain weight
- →Get a personalized TDEE based on your actual activity level, not generic estimates
- →Get a starting point for daily protein, carb, and fat targets before consulting a nutritionist
- →Track how your BMI changes week over week during a diet or training program
- →Quickly compare caloric needs at different activity levels to plan workouts accordingly
Tips
- ✓BMI is a screening tool — it does not account for muscle mass, bone density, or body fat distribution
- ✓Athletes and people with high muscle mass will often show a high BMI despite being healthy
- ✓Use the Calorie tab to calculate your TDEE based on your actual weekly activity, not aspirational levels
- ✓Macro targets are general guidelines — adjust protein upward if you are strength training
- ✓A deficit of 300–500 calories per day produces sustainable weight loss of roughly 0.3–0.5 kg per week
- ✓Recalculate every 4–6 weeks as your weight changes, since TDEE shifts with body weight
Frequently Asked Questions
BMI (Body Mass Index) is calculated by dividing your weight in kilograms by the square of your height in meters. In imperial, the formula is: BMI = 703 × weight(lb) / height(in)². The result categorizes body weight as underweight (<18.5), normal (18.5–24.9), overweight (25–29.9) or obese (≥30).
TDEE (Total Daily Energy Expenditure) is calculated using the Mifflin-St Jeor formula for Basal Metabolic Rate — the calories your body needs at rest — multiplied by an activity factor. Men: BMR = 10×weight + 6.25×height − 5×age + 5. Women: BMR = 10×weight + 6.25×height − 5×age − 161.
BMI is a useful screening tool but has limitations — it does not distinguish between muscle and fat mass. Highly muscular people may have a high BMI without excess body fat. For a complete picture, consult a healthcare professional.
The weight-loss target subtracts 500 kcal/day from your TDEE. A deficit of 500 kcal/day is generally associated with losing approximately 0.5 kg (1 lb) per week. The calculator enforces a minimum of 1,200 kcal/day.
The suggested macros use a general 30% protein / 40% carbs / 30% fat distribution applied to your daily calorie goal. These are guidelines — optimal ratios vary based on your training style, diet preference and individual metabolism.
Yes. Toggle between Metric (kg / cm) and Imperial (lb / ft + in) at any time. Values are converted automatically when you switch so you never have to re-enter your data.