Understanding your daily calorie needs is the foundation of any nutrition or weight management plan, whether your goal is weight loss, maintenance, or muscle gain. This calorie calculator computes your Basal Metabolic Rate (BMR), the energy your body needs at complete rest, using the widely accepted Mifflin-St Jeor or Harris-Benedict equations based on your age, sex, height, and weight. It then applies an activity multiplier to estimate your Total Daily Energy Expenditure (TDEE), giving you a realistic calorie target for your goals. Use these numbers as a starting point for meal planning, and adjust based on real-world results over a few weeks.