Calorie Calculator

What is a Calorie Calculator?

A calorie calculator estimates how much energy you need each day from your sex, age, height, weight, and activity level. It first works out your basal metabolic rate (BMR) - the minimum energy needed to keep your body running at rest - then multiplies it by an activity factor to give your total daily energy expenditure (TDEE). Whether you want to lose weight or build muscle, knowing your maintenance calories is the starting point for any eating plan. With calorie labels on packaged food and tracking apps now common, this tool gives a personalized figure that accounts for sex and age. Since one kilogram of body fat holds roughly 7,200 kcal, it also helps you plan a realistic, gradual rate of weight change.

How to Use

1. Select your sex. 2. Enter your age, height (cm), and weight (kg). 3. Select your daily activity level (from mostly sedentary up to very active). 4. Calculate to see your basal metabolic rate and your total daily energy expenditure (maintenance calories). To lose weight, eat about 300-500 kcal below maintenance per day; to gain, add a similar amount - both are sustainable rates.

Formula & Definition

The tool uses a widely adopted BMR estimate (the Mifflin-St Jeor equation): Men: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5 Women: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161 It then multiplies BMR by an activity factor to get TDEE: about 1.2 if sedentary, around 1.55 for moderate exercise, and up to 1.9 if very active. For example, a 30-year-old man who is 175 cm and 70 kg has a BMR of about 1,649 kcal, and with moderate exercise his maintenance is roughly 2,556 kcal.

Interpreting Results

Your maintenance calories (TDEE) are the daily energy needed to keep your current weight. Eat less and you trend toward weight loss; eat more and you gain. Because a kilogram of body fat is about 7,200 kcal, a steady deficit of 500 kcal a day works out in theory to roughly 1 kg lost in two weeks, though metabolic adaptation and water shifts make the real figure vary. Extreme restriction risks losing muscle and feeling unwell, so keep a deficit to about 15-20% below maintenance. The equation assumes average body composition, so it is off for people with much more or much less muscle than typical. Use the number as a starting point and fine-tune it by watching your weight trend over a few weeks.

Frequently Asked Questions