How to gain weight
You gain weight by eating more than you burn — a calorie surplus. Your daily target = maintenance calories + surplus. Since about 3,500 calories equals a pound, a 300-calorie daily surplus adds roughly 0.6 lb (0.27 kg) a week. From a 2,500 maintenance, that's eating 2,800 a day.
How to use this calculator
Enter your maintenance calories (from the maintenance calorie calculator) and the daily surplus you want. The result shows your target intake and estimated weekly gain in pounds and kilograms. Turn the daily total into food targets with the macro calculator.
Lean gains vs. fast gains
A moderate surplus of about 250–500 calories a day favours muscle over fat, especially paired with strength training and enough protein. Very large surpluses speed the scale but add more fat. Slower, steady gains are usually easier to keep lean. Gaining lean tissue rather than fat is easier to track with the lean body mass calculator.
Adjust to the trend
Bodies differ, so use your weekly weigh-in trend to fine-tune the surplus. If you're not gaining, add a little; if gaining too fast, ease back. This is a general estimate for information only, not medical or nutrition advice.
Frequently asked questions
- How do I calculate calories to gain weight?
- Add your chosen surplus to your maintenance calories. A 300-calorie surplus from a 2,500 maintenance means eating 2,800 a day, for about 0.6 lb of gain per week.
- How big should a surplus be?
- About 250–500 calories a day favours lean gains. Larger surpluses add weight faster but with more fat.
- How fast can I gain weight safely?
- Many aim for roughly 0.25–0.5% of body weight per week to keep gains lean, adjusting from the actual trend.
- Does protein matter for weight gain?
- Yes. Adequate protein and strength training help direct a surplus toward muscle rather than fat.
- What if I eat the surplus and still do not gain?
- Your real maintenance is probably higher than estimated, or intake is being under-counted. Add another 200-300 calories a day, weigh your food for a week, then recheck the trend. This is a general estimate, not medical advice.