Calculate Basal Metabolic Rate and daily calorie needs
BMR stands for Basal Metabolic Rate. In simple words, it's the number of calories your body needs to just stay alive when you're doing absolutely nothing โ lying completely still in a comfortable temperature, not digesting food, not even thinking too hard. It's the energy your heart, lungs, kidneys, liver, brain and all other organs need just to keep functioning.
For most people, BMR accounts for about 60-75% of total daily calorie expenditure. Which means even on a rest day, your body is burning a significant amount of calories just to keep you alive. This is good to know when you're planning your diet.
There are several formulas to calculate BMR, and they give slightly different results. Our calculator offers three options:
The Mifflin-St Jeor equation (1990) is considered the most accurate for most people. Multiple studies have validated it as the best predictor of resting metabolic rate. This is what we recommend for most users.
The Harris-Benedict equation (revised 1984) is older but still widely used. It tends to overestimate slightly compared to Mifflin-St Jeor.
The Katch-McArdle formula is unique because it's based on lean body mass rather than total body weight. If you know your body fat percentage, this can be more accurate โ especially for muscular people or athletes whose high muscle mass might throw off weight-based formulas.
BMR is just the baseline. Your Total Daily Energy Expenditure (TDEE) is what you actually burn in a day, accounting for your activity level. TDEE = BMR ร Activity Multiplier.
The activity multipliers are: Sedentary (desk job, no exercise) = 1.2 ร BMR. Light activity (1-3 days/week exercise) = 1.375. Moderate activity (3-5 days/week) = 1.55. Very active (6-7 days/week hard exercise) = 1.725. Extremely active (physical job + twice daily training) = 1.9.
Most office-going Indians fall in the sedentary to light activity category, honestly. If you're not specifically exercising, sitting at a desk 8+ hours counts as sedentary.
Once you know your TDEE, weight management becomes pretty straightforward in theory:
For weight loss: eat 500 calories below your TDEE per day. This creates roughly a 3,500 calorie weekly deficit, which corresponds to about 0.5 kg of fat loss per week. Don't go below your BMR โ that can actually slow down your metabolism over time.
For weight gain: eat 300-500 calories above your TDEE. This supports muscle growth without excessive fat gain. Combined with strength training, this is how people build muscle effectively.