Building healthy weight requires a controlled calorie surplus rather than guesswork. This free online weight gain calculator calculates how much weight you need to gain, your weekly rate of gain, and the daily calorie surplus needed to reach your goal weight in your chosen time frame. It also warns you if your target pace is likely to add excess fat, so you can plan a leaner, more gradual gain.
Find out how much of a daily calorie surplus you need to reach your goal weight in your chosen time frame.
How to Use the Weight Gain Calculator
Enter your current weight in kilograms in the "Current Weight (kg)" field.
Enter your target goal weight, which must be higher than your current weight, in the "Goal Weight (kg)" field.
Enter your desired time frame in weeks in the "Time Frame (weeks)" field.
Click "Calculate Weight Gain Plan" to view the weight to gain, your weekly rate, and the daily calorie surplus needed.
If a warning shows about gaining more than 0.5 kg per week, try a longer time frame for a leaner gain.
Frequently Asked Questions
The calculator estimates that gaining one kilogram of body weight requires about 7,700 extra kcal. It multiplies the total weight you need to gain by 7,700, then divides by the total number of days in your chosen time frame to give a daily calorie surplus target.
The calculator will show the message "Goal weight should be greater than your current weight" instead of a plan, since a weight gain goal must be higher than where you're starting from.
If your calculated weekly rate works out to more than 0.5 kg (1.1 lb) per week, the calculator warns that this pace is likely to include a significant amount of fat, and suggests a longer time frame for a leaner gain.
Yes, it's completely free with no sign-up required. You just need your current weight, goal weight (both in kilograms), and your desired time frame in weeks.