What is BMI & Calorie Calculator?
This calculator does two related jobs. It works out your Body Mass Index from your height and weight, tells you which WHO category that falls into, and shows the weight range considered healthy for your height. It then estimates your Basal Metabolic Rate using the Mifflin-St Jeor equation, multiplies it by your activity level to give your maintenance calories, and adjusts that figure for a weight loss or weight gain goal. Both metric and imperial units are supported.
How to Use
Choose metric or imperial, then enter your height and weight to see your BMI.
Add your age and gender so the calculator can estimate your BMR.
Pick your activity level and goal to get a daily calorie target.
Why Use This Tool?
Most BMI tools stop at a single number without saying what to do with it. This one also gives you the calorie figure that actually drives weight change, using Mifflin-St Jeor - the equation dietitians generally consider the most accurate for people without body-fat measurements. It also refuses to suggest an unsafe deficit, raising any target below 1,500 kcal for men or 1,200 kcal for women. Everything is calculated in your browser and nothing is stored.
FAQ
BMI is your weight in kilograms divided by the square of your height in metres. A 70 kg person who is 1.72 m tall has a BMI of 70 ÷ (1.72 × 1.72) = 23.7.
Under the WHO scale, below 18.5 is underweight, 18.5 to 24.9 is normal weight, 25 to 29.9 is overweight, and 30 or above is obese. Some Asian health guidelines, including India's, use lower thresholds of 23 for overweight and 25 for obesity, so read your result alongside local medical advice.
No. BMI does not distinguish muscle from fat, so athletes often read as overweight while someone with low muscle mass may read as normal despite excess body fat. It is a population-level screening measure, not a diagnosis - treat it as one signal among several.
BMR is what your body burns at complete rest just to keep functioning. Maintenance calories, or TDEE, is your BMR multiplied by an activity factor, and it represents what you actually burn in a normal day. Eating at your maintenance level keeps your weight stable.
A deficit of about 500 kcal a day corresponds to roughly half a kilogram of weight loss per week. Larger deficits are harder to sustain and risk muscle loss. This calculator will not suggest a target below 1,500 kcal for men or 1,200 kcal for women.
Treat them as a starting point. Real calorie needs vary with body composition, medication, thyroid function, and pregnancy. Check with a doctor or registered dietitian before making significant changes, especially if you have a medical condition.