Calorie Calculator
Your Total Daily Energy Expenditure (TDEE) is the number of calories your body burns in a full day, combining your Basal Metabolic Rate (BMR) with your activity level. BMR is calculated using the Mifflin-St Jeor equation, the formula most widely endorsed by Australian dietitians, which accounts for height, weight, age, and sex. TDEE is then derived by multiplying BMR by an activity factor ranging from sedentary (×1.2) to extremely active (×1.9). To lose weight, you consume fewer calories than your TDEE; to gain muscle, more. A deficit of roughly 2,000 kJ (500 cal) per day produces approximately 0.5 kg of fat loss per week, the rate most dietitians consider sustainable without muscle loss. This calculator shows your TDEE across all activity levels, plus recommended intake for weight loss, maintenance, and muscle gain.
Frequently Asked Questions
How many calories does the average person need?
The average sedentary adult woman needs roughly 1,600-2,200 calories per day and the average sedentary adult man needs roughly 2,000-3,000 calories per day to maintain weight. This varies significantly based on age, height, weight, muscle mass, and activity level. A 5'4" sedentary 30-year-old woman might maintain at around 1,800 calories, while a 6'2" muscular 25-year-old man who exercises regularly might need 3,000-3,500. Many countries outside the US display nutrition information in kilojoules as well (1 calorie = 4.184 kilojoules). The only way to truly know your needs is to track your weight and intake over several weeks and adjust accordingly.
What is basal metabolic rate (BMR)?
BMR is the number of calories your body burns at complete rest, just to keep vital organs functioning (breathing, circulation, cell production, and so on). It accounts for 60-75% of your total daily energy expenditure. BMR is determined by your age, sex, weight, and muscle mass. Muscle tissue burns significantly more calories at rest than fat tissue, which is why strength training indirectly supports long-term weight management by increasing muscle mass. BMR is usually calculated using the Mifflin-St Jeor equation, considered the most accurate of the common formulas for people who are not extremely lean or extremely overweight. Your BMR can be measured precisely through indirect calorimetry (breath analysis) at some health clinics.
How accurate are calorie counters on gym equipment?
Calorie counters on gym equipment (treadmills, ellipticals, rowing machines) are often significantly inaccurate, overestimating calorie burn by 15-30% or more. This is because they use generic formulae based on an assumed average fitness level and body composition. A 40-year-old overweight person burning 300 calories according to the machine might actually burn closer to 200-220. Use these numbers as a very rough guide only. For more accurate measurement, consider a fitness tracker with a heart rate sensor, or better yet, use your calculated TDEE as the baseline and track weight changes over 3-4 weeks to determine your actual maintenance intake. Many fitness studios and personal trainers offer indirect calorimetry testing for a more precise BMR measurement.
Will eating fewer calories make me lose weight?
Generally yes, but the relationship is more nuanced than simply eating less. A calorie deficit of 3,500 calories roughly equals 0.5 kg of body weight loss, so a daily deficit of 500 calories should result in about 0.5 kg per week. However, severely restricting calories (below 1,500 for men or 1,200 for women) can cause metabolic slowdown, muscle loss, nutritional deficiencies, and make sustained weight loss harder. The body adapts to prolonged calorie restriction by burning fewer calories. A better approach is to start at your estimated TDEE, create a moderate deficit of 20-25%, monitor your weight for 3-4 weeks, and adjust from there based on actual results rather than theoretical calculations.
Is a calorie just a calorie?
From a pure physics standpoint, yes: a calorie is a unit of energy and 100 calories of broccoli theoretically provides the same energy as 100 calories of soft drink. However, the two affect hormones, satiety, blood sugar, and metabolism very differently. The 200 calories in a handful of almonds come with protein, fibre, and healthy fats that keep you full for hours, while 200 calories of soft drink causes a rapid blood sugar spike and crash, leaving you hungry again within an hour. Additionally, the thermic effect of food (energy used to digest it) differs: protein requires more energy to digest than carbohydrates. This is why food quality matters alongside quantity for sustainable weight management and overall health.
What are macros and do I need to count them?
Macros (macronutrients) are the three energy-providing nutrients: protein (4 calories per gram), carbohydrates (4 calories per gram), and fat (9 calories per gram). Protein is essential for muscle repair and immune function; carbs are your body's preferred fuel for high-intensity exercise; fat is needed for hormone production and nutrient absorption. Counting macros is useful for athletes, people building muscle, or those with specific performance goals. For most people, focusing on total calorie intake is sufficient for weight management. A balanced starting point is roughly 30% protein, 40% carbs, and 30% fat, though optimal ratios depend on your activity level and goals. Most nutrition labels display per-serving macro breakdowns to help you track intake.