Calorie Intake Calculator

How we calculate your calorie needs

This calculator uses the Mifflin-St Jeor equation, which research published in the Journal of the American Dietetic Association has identified as the most reliable formula for estimating Basal Metabolic Rate (BMR) in healthy adults. BMR represents the calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell repair. The formula is: For men: BMR = 10 x weight (kg) + 6.25 x height (cm) - 5 x age + 5. For women: BMR = 10 x weight (kg) + 6.25 x height (cm) - 5 x age - 161. Your BMR is then multiplied by an activity factor — ranging from 1.2 for sedentary lifestyles to 1.9 for extremely active individuals — to estimate your Total Daily Energy Expenditure (TDEE). For weight loss, we apply a moderate deficit of 500 kcal per day, which aligns with guidelines from the National Institutes of Health for safe, sustainable weight loss. For weight gain, a surplus of 500 kcal is added. These adjustments are starting points that should be fine-tuned based on your individual response over time.

What your result means

Your recommended calorie intake is a personalized estimate based on your age, sex, height, weight, activity level, and goal. According to guidelines from the National Institutes of Health, a daily deficit of 500 calories typically produces approximately 0.5 kg (1 lb) of weight loss per week, which is considered a safe and sustainable rate. For weight gain, a surplus of 500 calories per day supports gradual lean mass increases when combined with resistance training. It is important to note that these are evidence-based starting points, not exact prescriptions. Individual metabolism varies due to genetics, hormonal factors, sleep quality, stress levels, and body composition. Your actual calorie needs may be 10 to 15 percent higher or lower than the estimate. The most effective approach is to follow your recommended intake for two to four weeks, monitor your weight trend, and then adjust up or down by 100 to 200 calories as needed. Avoid dropping below 1,200 kcal per day for women or 1,500 kcal per day for men without medical supervision, as very low intakes can impair metabolic function.

Frequently Asked Questions