Calorie & Macro Calculator
Estimate your daily calorie needs and macronutrient targets using the Mifflin-St Jeor equation. Adjust for activity level and goal.
Frequently Asked Questions
What formula does this calculator use?
The Mifflin-St Jeor equation (1990) is used to calculate BMR. For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161. BMR is then multiplied by an activity factor (1.2 to 1.9) to produce TDEE. Research shows Mifflin-St Jeor is the most accurate equation for most people.
How are macros calculated?
Protein is set at 1.6 g per kg of body weight — a target well-supported by exercise science for muscle retention and growth. Fat provides 25% of total calories (each gram of fat = 9 kcal). Carbohydrates fill the remaining calories (each gram = 4 kcal). These are starting-point guidelines; adjust based on personal response and dietary preferences.
How accurate are the results?
Predictive equations estimate average needs for a population. Individual variation in metabolism, body composition, hormones, and genetics can shift actual requirements by 10–20%. Use the results as a starting point: track your intake for 2–4 weeks, then adjust calories up or down by 100–200 kcal based on your progress.