Uses the Mifflin-St Jeor equation. Estimate only — individual needs vary.
What is a calorie calculator, and who needs it?
A calorie calculator estimates how much energy your body uses in a day. First it works out your basal metabolic rate (BMR), the calories you burn at rest. Then it scales that by your activity level to get your maintenance calories, also called total daily energy expenditure (TDEE). From there it suggests lower targets for weight loss and a higher one for weight gain.
It is useful for anyone planning their eating: gym-goers building a diet, people trying to lose belly fat, students and IT professionals with desk jobs who want to understand why weight creeps up, and thin people who struggle to gain. It gives you a number to start from instead of guessing.
Formula used
The calculator uses the Mifflin-St Jeor equation, with weight in kg, height in cm and age in years:
- Men: BMR = 10 × weight + 6.25 × height − 5 × age + 5
- Women: BMR = 10 × weight + 6.25 × height − 5 × age − 161
- TDEE = BMR × activity factor
The activity factors are 1.2 (sedentary), 1.375 (light), 1.55 (moderate), 1.725 (active) and 1.9 (very active). Mild loss is TDEE − 250, weight loss is TDEE − 500, and weight gain is TDEE + 500.
Worked example
Take a 25-year-old man, 170 cm tall, weighing 70 kg, with moderate activity (1.55).
- BMR = 700 + 1,062.5 − 125 + 5 = 1,642.5 kcal
- TDEE = 1,642.5 × 1.55 = about 2,546 kcal per day
- Mild loss = about 2,296, weight loss = about 2,046, weight gain = about 3,046
Now a 28-year-old woman, 160 cm, 62 kg, light activity (1.375). BMR = 620 + 1,000 − 140 − 161 = 1,319 kcal. TDEE = 1,319 × 1.375 = about 1,814 kcal. Her mild loss target is about 1,564, weight loss about 1,314, and weight gain about 2,314.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is the energy your body burns at complete rest to keep you alive. TDEE is BMR multiplied by an activity factor, so it includes walking, work and exercise. The maintenance figure shown by this calculator is your TDEE.
Which activity level should I choose?
Pick the level that matches your usual week, not your best week. If you sit at a desk most of the day and walk or train only occasionally, Sedentary or Light is usually more honest than Moderate.
How many calories should I cut to lose weight?
A deficit of 250 to 500 calories a day is a common starting point and usually means a loss of roughly 0.25 to 0.5 kg a week. Larger cuts are harder to sustain and should be discussed with a doctor or dietitian.
Do I need to recalculate as my weight changes?
Yes. As your weight, age or activity changes, so does your energy need. Recalculate after every few kilograms lost or gained, or when your routine changes.
Does this work for Indian food like roti, rice and dal?
Yes. Calories are the same whatever the cuisine. The calculator only gives your daily target, which you can compare with food labels or a nutrition database for home-cooked meals.
Limitations and accuracy
The Mifflin-St Jeor equation was built from studies done mostly outside India, and it can be off by 10 percent or more for an individual. It cannot see your muscle mass, thyroid health, medicines or pregnancy, and it depends on you choosing an honest activity level. Treat the numbers as a starting point, watch your real weight trend for two to three weeks, and adjust. Children, pregnant or breastfeeding women, and people with medical conditions should speak to a doctor or dietitian first.