Find exactly how many calories to eat every day to gain weight steadily — your maintenance calories, a healthy surplus, a full protein/carb/fat breakdown, and how many weeks it'll take to hit a target weight.
Key Takeaways
- Weight gain is maintenance calories plus a surplus, the mirror image of weight loss — find your TDEE first, then add calories on top rather than guessing.
- A smaller, steadier surplus builds more muscle relative to fat. A large surplus makes the number on the scale move faster, but a bigger share of that gain tends to be fat rather than lean tissue.
- Protein intake matters more than total calories alone for how much of the weight gained is muscle — roughly 1.6 to 2.2 grams of protein per kilogram of body weight is the commonly cited range for anyone strength training while in a surplus.
What This Calorie Calculator Does
This calculator works out how many calories you need to eat every day to gain weight steadily and healthily. It starts with your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest — using the Mifflin-St Jeor equation, then scales it up by your activity level to find your maintenance calories (TDEE). From there, it adds a calorie surplus sized to whichever gain rate you choose, and breaks that total down into protein, carbohydrate, and fat targets in grams, which matters more than the total number alone if the goal is building muscle rather than just gaining weight in any form. Pick a Diet Preference (Vegetarian, Eggetarian, Non-Vegetarian, or Vegan) and the calculator also shows your daily calorie surplus translated into everyday Indian foods — rotis, rice, dal, paneer, milk, or eggs and chicken depending on your choice — so the number on the screen turns into something you can actually picture on a plate. If you enter a target weight, it also estimates how many weeks it will take to get there.
Everything runs entirely in your browser. No age, weight, or activity level you enter is sent to a server, logged, or stored anywhere — close the tab and it's gone. There's no signup, no email wall, and no ads inside the calculator itself. This is an estimate for general fitness and nutrition planning, not medical advice — the disclaimer above the results is there for a reason.
How to Use This Calorie Calculator
1. Enter Your Details
- Select Gender, then enter Age and Height.
- Enter your Current Weight.
- Optionally enter a Target Weight to see a timeline.
2. Choose Activity & Gain Rate
- Pick the Activity Level that best matches your week.
- Pick a Rate of Weight Gain — Mild, Moderate, or Fast.
- Your daily calorie target updates instantly.
3. Read Your Macro Breakdown
- Check the Protein / Carb / Fat grams in the donut chart.
- See the weeks-to-target estimate if you entered a target weight.
- Use Download as .txt to save your targets for tracking.
The Calorie Calculation, Explained
Step 1 — BMR (Mifflin-St Jeor equation):
Men: BMR = 10W + 6.25H − 5A + 5 | Women: BMR = 10W + 6.25H − 5A − 161
Where W is weight in kg, H is height in cm, and A is age in years.
Step 2 — TDEE: BMR × Activity Multiplier (1.2 to 1.9 depending on activity level).
Step 3 — Surplus: Target weekly gain (kg) × 7700 ÷ 7, added to TDEE. (7700 kcal is the commonly used approximation for 1 kg of body mass.)
Worked example: Male, 25 years, 175 cm, 60 kg, Moderate activity, Moderate gain rate.
- BMR = (10 × 60) + (6.25 × 175) − (5 × 25) + 5 = 1,574 kcal
- TDEE = 1,574 × 1.55 ≈ 2,439 kcal
- Surplus = 0.5 × 7700 ÷ 7 ≈ 550 kcal
- Daily Target = 2,439 + 550 ≈ 2,989 kcal
Using 1.8g of protein per kg body weight (60 × 1.8 = 108g = 432 kcal) and 25% of total calories from fat (747 kcal ≈ 83g), the remaining 1,810 kcal (≈ 452g) comes from carbohydrates.
TDEE & Gain-Rate Reference Table
For a BMR of 1,574 kcal (the worked example above), here's how maintenance calories and gain targets shift across activity levels and gain rates.
| Activity Level | TDEE (Maintenance) | Mild Gain (+275) | Moderate Gain (+550) | Fast Gain (+825) |
|---|---|---|---|---|
| Sedentary | 1,889 | 2,164 | 2,439 | 2,714 |
| Light | 2,164 | 2,439 | 2,714 | 2,989 |
| Moderate | 2,439 | 2,714 | 2,989 | 3,264 |
| Active | 2,715 | 2,990 | 3,265 | 3,540 |
| Very Active | 2,990 | 3,265 | 3,540 | 3,815 |
Quick Definitions
BMR (Basal Metabolic Rate) is the number of calories your body burns just to keep essential functions running at complete rest, before any activity is counted. TDEE (Total Daily Energy Expenditure) is your BMR scaled up by an activity multiplier to reflect exercise and daily movement — it's the calorie total at which your weight stays stable, and the baseline this calculator adds a surplus to for weight gain.
Frequently Asked Questions
The most common reason is that your actual intake is lower than estimated, since it's easy to underestimate portion sizes and forget snacks or drinks. Your activity level or metabolism may also run higher than the multiplier assumes. Track your intake for a week or two and adjust the target upward if the scale isn't moving.
A commonly cited range for anyone strength training in a calorie surplus is 1.6 to 2.2 grams of protein per kilogram of body weight per day. This calculator defaults to 1.8g/kg as a reasonable middle ground.
Common calorie- and protein-dense vegetarian staples include paneer, dals and legumes, milk and dairy, nuts and seeds, ghee, whole grains like rice and roti, and bananas or other energy-dense fruits. This is general information, not a personalised diet plan — a dietitian can tailor specific quantities to your targets.
Not usually. A larger calorie surplus does make the scale move faster, but more of that gain tends to be fat rather than muscle. A mild-to-moderate surplus (0.25–0.5 kg/week) is generally recommended for a leaner gain, with faster rates reserved for short, deliberate phases.
It's generally considered one of the more accurate BMR equations for the general population and is widely used in nutrition science, but any formula is still an estimate — individual metabolism can vary by a meaningful margin either way, which is why tracking your actual results over a few weeks matters more than the formula alone.
No. Every calculation runs locally in your browser using JavaScript; nothing you enter is transmitted to any server, logged, or saved once you close or refresh the page.