Most people need to eat roughly 300 to 500 calories above their maintenance level each day to gain weight at a steady, sustainable pace. That translates to about 2,000 to 3,500 extra calories per week, which is enough to add 0.5 to 1 pound. The exact number depends on your body size, age, sex, and how active you are, so the real starting point is figuring out how many calories your body burns in a typical day.
Finding Your Maintenance Calories
Your maintenance calories, sometimes called your total daily energy expenditure, represent the number of calories your body uses just to keep you at your current weight. This includes everything from breathing and digestion to walking around and exercising. To gain weight, you need to consistently eat more than this number.
The most widely used method for estimating maintenance calories starts with a formula called the Mifflin-St Jeor equation, which calculates how many calories your body burns at complete rest. For men, the formula is (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For women, it’s the same but you subtract 161 instead of adding 5. You then multiply that resting number by an activity factor: 1.2 if you’re sedentary, 1.375 if you’re lightly active, 1.55 for moderate activity, 1.725 for regular hard exercise, and 1.9 if you’re very active or have a physically demanding job.
As a quick example, a moderately active 30-year-old man who weighs 154 pounds (70 kg) and stands 5’10” (178 cm) would have a resting calorie burn of about 1,600, and a maintenance level around 2,480 calories per day. To gain weight, he’d aim for roughly 2,800 to 3,000 calories daily.
How Big Your Surplus Should Be
The size of your surplus depends on your goal. If you want to gain mostly lean muscle with minimal fat, a smaller surplus of 250 to 350 calories per day works best. It takes roughly 2,000 to 2,500 extra calories per week to support a pound of lean muscle gain. A larger surplus of 500 or more calories per day will produce faster weight gain, but a greater share of it will be fat, since gaining a pound of fat requires about 3,500 excess calories per week.
For most people, a moderate surplus of 300 to 500 calories per day strikes the right balance between noticeable progress and limiting unnecessary fat gain. If you’re underweight and your primary goal is simply getting to a healthier body weight, leaning toward the higher end is reasonable. If you’re already at a normal weight and trying to add muscle, staying closer to 250 to 350 extra calories keeps things leaner.
What a Healthy Rate of Gain Looks Like
A good target is gaining 0.25% to 0.5% of your body weight per week. For a 175-pound man, that’s about 0.4 to 0.8 pounds per week. For a 135-pound woman, it’s closer to 0.3 to 0.6 pounds per week. At this rate, a 10-pound gain takes roughly 3 to 6 months.
Weigh yourself once a week under consistent conditions, ideally in the morning before eating. Daily fluctuations in water, sodium, and digestion can swing the scale by a pound or two in either direction, so weekly averages give you a much clearer picture than day-to-day numbers. If your weight hasn’t budged after two to three weeks, add another 200 to 300 calories per day and reassess. If you’re gaining faster than 1% of your body weight per week, you’re likely adding more fat than necessary.
Where Your Extra Calories Should Come From
Protein is the most important macronutrient for weight gain, especially if you want that weight to include muscle. Aim for roughly 1.2 to 1.6 grams of protein per kilogram of body weight each day (about 0.5 to 0.7 grams per pound). For a 180-pound person, that’s 90 to 130 grams of protein daily. Going above 2 grams per kilogram hasn’t shown clear muscle-building benefits and may carry health risks over the long term.
How you distribute that protein throughout the day matters. Research on muscle protein synthesis shows that your body can only use about 30 to 45 grams of protein per meal to build muscle tissue. Eating beyond that amount in a single sitting doesn’t increase the muscle-building response. Spreading your protein evenly across three or four meals, rather than loading most of it into dinner, stimulates significantly more muscle growth over a 24-hour period. So a pattern of 30 grams at breakfast, 30 at lunch, and 30 at dinner outperforms eating 10 grams in the morning and 65 at night, even if the daily total is the same.
Fill the rest of your surplus with a mix of healthy fats and carbohydrates. Calorie-dense foods make it much easier to hit a higher target without feeling uncomfortably full all day.
High-Calorie Foods That Make It Easier
One of the biggest practical challenges of gaining weight is simply eating enough. If you’re not used to large meals, calorie-dense foods help you get more energy in smaller volumes. Some of the most useful options include:
- Nuts and nut butters: Two tablespoons of peanut butter alone pack nearly 200 calories. Almonds, walnuts, and cashews are similarly dense.
- Olive oil and cooking oils: A single tablespoon adds about 120 calories to any dish.
- Avocados: One medium avocado provides roughly 240 calories along with healthy fats.
- Dried fruit: Raisins, dates, and apricots concentrate the calories of fresh fruit into a much smaller serving.
- Fatty fish: Salmon, tuna, and sardines offer both calories and protein.
- Seeds: Chia seeds, flaxseed, and sunflower seeds add calories and nutrients to yogurt, oatmeal, or smoothies.
To put this in perspective, a smoothie made with Greek yogurt, a banana, milk, a scoop of protein powder, and a tablespoon of peanut butter comes in around 538 calories. A bowl of oatmeal cooked with milk, honey, banana, and raisins hits about 458. A turkey sandwich with avocado and mayonnaise is roughly 555. Meals like these make a 500-calorie surplus feel manageable rather than forced.
Meal Frequency and Timing
Eating more frequently, typically four to six times per day, is one of the simplest ways to increase total intake. It’s much easier to eat 3,000 calories spread across five meals than crammed into three. If you struggle with appetite, adding a mid-morning snack, an afternoon snack, and something before bed can add 500 to 800 calories without requiring any single meal to be enormous.
A trail mix with almonds, walnuts, raisins, and cereal provides about 370 calories. Two graham crackers with peanut butter and a glass of milk come in at roughly 390. Greek yogurt topped with granola and chia seeds is about 338. Snacks like these are easy to eat even when you don’t feel particularly hungry, and they add up quickly over the course of a day.
When Progress Stalls
Weight gain plateaus are normal and don’t always mean you need to eat more. As you gain weight, your body burns slightly more calories at rest simply because there’s more tissue to maintain. Your maintenance level gradually rises, which can shrink your surplus over time.
If the scale hasn’t moved for two to three weeks and your food intake has been consistent, add 200 to 300 calories per day. That might be as simple as an extra tablespoon of olive oil at dinner and a handful of nuts in the afternoon. If your strength in the gym is still improving, though, your body is likely still building muscle even if the scale isn’t moving much. Strength gains are a reliable signal that the process is working, and short plateaus often resolve on their own within a few weeks without any dietary changes.