Weight Gain Calculator

To gain weight, you must consume a calorie surplus — eating more calories than your body burns (TDEE). A surplus of 250 to 500 calories per day is typically recommended to promote a steady, healthy rate of gain (about 0.5 to 1.0 pound per week).

BMR (Basal Metabolic Rate) is the baseline number of calories your body burns at rest to keep you alive. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by your physical activity level. Your TDEE is the 'maintenance' calorie count you must exceed to gain weight.

The calculator estimates your BMR using the Mifflin-St Jeor equation (based on age, sex, weight, and height). It multiplies BMR by your physical activity factor to estimate TDEE. Finally, it adds the surplus calories needed to achieve your target weekly rate of gain (assuming 1 pound of weight gain requires a total surplus of ~3,500 calories).

For most people, a slow and steady rate of 0.25 to 0.5 pounds per week (or 0.1 to 0.25 kg/week) is ideal. This helps ensure that the weight gained is a mix of muscle mass and healthy tissue, rather than excessive body fat.

Focus on nutrient-dense, calorie-dense foods (nuts, seeds, avocados, whole grains, and lean proteins). Ensure you consume adequate protein (typically 0.8 to 1.0 gram per pound of body weight) and combine your diet with resistance training to promote muscle growth.