Weight Gain Tools
Numbers beat guesswork. Our free weight gain calculator takes the guessing out of bulking — enter your stats and it estimates the calories you need each day to gain weight at the pace you choose.
The single biggest reason people "can't gain weight" is that they don't actually know how many calories they're eating — or how many they need. Our weight gain tools fix that. Instead of guessing, you get a target: your maintenance calories (TDEE) plus the exact daily surplus that matches the rate you want to gain.
The flagship tool below is a free weight gain calorie calculator. It uses the same energy-balance principles described by the NIH/NIDDK and the Dietary Guidelines for Americans — roughly 3,500 calories per pound of body weight — and turns them into a personal daily number in seconds. No account, no email, no cost.
Once you have your target, pair it with one of our weight gain guides to turn the number into real meals and training. More free tools are on the way — but the calorie calculator is the one to start with.
Free weight gain calculator
Start with the calorie calculator below. We're adding more tools — a protein target estimator and a goal-date planner are next.
Weight Gain Calorie Calculator
Enter your age, height, weight, sex and activity level to get your maintenance calories and the exact daily surplus to gain weight at the pace you want — free, instant, no sign-up.
Open the calculator →Calorie Surplus Calculator
Turn your TDEE and chosen surplus into target calories, weekly gain rate and macros.
Open the calculator →Protein Calculator
Your daily protein target in grams to build muscle and gain lean weight.
Open the calculator →BMR & TDEE Calculator
Find your basal metabolic rate and maintenance calories in seconds.
Open the calculator →Weight Gain Goal Calculator
See how long it takes to reach your goal weight at your surplus.
Open the calculator →Pregnancy Weight Gain Calculator
Healthy gain range by trimester and pre-pregnancy BMI, per IOM guidance.
Open the calculator →Informational, not medical advice. These tools give general educational estimates, not personalized medical or nutrition advice. If you are underweight, have lost weight unintentionally, or have a health condition, consult a doctor or registered dietitian before changing your diet or training. Operator: Mustafa Bilgic.
New to gaining weight? Read How to Gain Weight Fast and the full weight gain guides hub, or take a fun break with our free weight gain games.
Get your daily calorie target
Stop guessing how much to eat. Run the free weight gain calorie calculator and get your exact daily number in seconds.