Weight Gain Calculator

To gain weight, you need to consume more calories than your body burns each day — this is called a calorie surplus. A surplus of roughly 500 kcal/day above your Total Daily Energy Expenditure (TDEE) typically leads to about 0.5 kg of weight gain per week. The exact number depends on your age, gender, height, weight, and activity level.

TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a day, including activity. To gain weight, you need to eat above your TDEE. Knowing your TDEE gives you a precise baseline so you can set a realistic and controlled calorie surplus.

A healthy rate of weight gain is generally 0.25–0.5 kg per week for most people. Gaining faster than this increases the risk of accumulating excess body fat rather than lean muscle mass. Spreading your goal over a longer timeframe with consistent training and nutrition produces better body composition results.

Yes — being underweight is associated with a weakened immune system, nutritional deficiencies, bone density loss, hormonal disruption, and reduced muscle mass. If your BMI falls below 18.5, it's worth consulting a healthcare professional to rule out underlying medical causes.

For muscle gain, a common recommendation is 1.6–2.2 g of protein per kg of body weight per day. The minimum threshold is around 0.8 g/kg, but this is insufficient for those actively trying to build muscle. Protein supports muscle protein synthesis, especially when combined with resistance training.

Focus on nutrient-dense, calorie-rich foods such as nuts, nut butters, avocados, whole milk dairy, eggs, lean meats, oily fish, legumes, whole grains, and healthy oils. Liquid calories like smoothies and milk shakes can also help increase intake without feeling overly full. Avoid relying heavily on processed junk food, which provides empty calories with poor nutritional value.

Absolutely. Resistance training (weight lifting) is the most effective way to ensure the extra calories you consume are converted into muscle rather than fat. Without exercise, a calorie surplus will largely result in fat gain. Aim for at least 3 resistance training sessions per week targeting all major muscle groups.

Yes — eating exactly at your TDEE (maintenance calories) will keep your weight stable over time. This calculator shows your TDEE so you can use it as a reference point. Keep in mind that TDEE is an estimate and your actual needs may vary slightly day to day.