To gain muscle, most people need to eat roughly 200 to 500 calories above their maintenance level each day while following a consistent resistance training program. That maintenance level, called your total daily energy expenditure (TDEE), varies based on your size, age, sex, and activity level, so there’s no single number that works for everyone. But the formula for figuring out your personal target is straightforward.
How to Find Your Starting Number
Your body burns calories through three main channels. Resting metabolism, the energy needed just to keep your organs running, accounts for 60 to 70 percent of your daily burn. Digesting food uses about 10 percent. Physical activity covers the rest, ranging from 15 percent in sedentary people up to 50 percent in highly active individuals.
The simplest way to estimate your TDEE is to multiply your body weight in pounds by an activity factor. If you train hard three to five days per week, multiplying by 15 to 17 gives a reasonable ballpark. A 170-pound person training regularly, for example, lands somewhere between 2,550 and 2,890 calories per day as a maintenance estimate. From there, adding 200 to 500 calories creates the surplus your body needs to build new tissue.
Online TDEE calculators that use the Mifflin-St Jeor or Harris-Benedict equations can sharpen this estimate by factoring in your age, height, and sex. But any formula is still just a starting point. The real calibration happens over the next few weeks as you track your weight and adjust.
Why a Moderate Surplus Beats a Large One
Eating more does not automatically mean building more muscle. A study of 600 elite athletes compared a group that significantly increased calories to one that maintained a normal diet. Both groups improved their lifting strength at the same rate and gained similar amounts of muscle. The only difference: the overeating group increased body fat by 15 percent, while the maintenance group gained just 2 percent.
This is the core problem with aggressive “dirty bulking.” In overfeeding studies on sedentary populations, 60 to 70 percent of the weight gained was fat mass, not muscle. While athletes respond differently than sedentary subjects, the takeaway is clear: your body has a ceiling for how fast it can synthesize new muscle protein, and extra calories beyond that ceiling get stored as fat. A surplus of 200 to 300 calories per day is enough for most people. Those who are newer to training or naturally lean may push toward 400 to 500 without excessive fat gain.
How Much Muscle You Can Realistically Gain
A large meta-analysis of 111 resistance training studies found that healthy adult males gained an average of 1.53 kilograms (about 3.4 pounds) of muscle over the course of a training program. But the rate depends heavily on experience.
People who were physically active but had never lifted weights gained the most, averaging 1.92 kg (4.2 pounds). Complete beginners gained about 1.39 kg (3.1 pounds). Intermediate lifters with one to three years of training experience showed smaller, less consistent gains. Interestingly, advanced lifters with four or more years of experience gained an average of 2.96 kg, likely because they had the training knowledge and intensity to push past plateaus.
For practical planning, beginners can expect roughly 1 to 2 pounds of muscle per month during their first year. Intermediate lifters slow to about 0.5 to 1 pound per month. This matters for setting your surplus: if your body can only build a pound of muscle in a month, eating as though it can build five will just accelerate fat storage.
Protein Is the Priority Macronutrient
Total protein and total calorie intake are the two most important dietary factors for building muscle. Timing strategies like eating immediately before or after a workout appear to have minimal impact for most people.
The current research points to a daily protein target of 1.6 to 2.2 grams per kilogram of body weight for maximizing muscle growth with resistance training. For a 170-pound (77 kg) person, that works out to about 123 to 170 grams of protein per day. Spreading this across meals helps too. Roughly 0.4 grams per kilogram of body weight per meal (about 30 to 35 grams for most people) is enough to maximally stimulate muscle protein synthesis at each sitting.
If you’re ever in a phase where you’re trying to build muscle while losing fat (body recomposition), protein needs go higher, up to 2.3 to 3.1 grams per kilogram per day, to protect existing muscle during the calorie deficit.
Carbs, Fats, and the Full Picture
Once protein is locked in, the remaining calories should come primarily from carbohydrates. Carbs fuel intense training sessions, and running low on them directly undermines your ability to train hard enough to stimulate growth. Research on bodybuilders suggests 55 to 60 percent of total calories from carbohydrates, 25 to 30 percent from protein, and 15 to 20 percent from fat during a building phase.
For someone eating 3,000 calories per day, that looks roughly like 410 to 450 grams of carbs, 190 to 225 grams of protein, and 50 to 67 grams of fat. These aren’t rigid rules. The protein target matters most. After that, your carb-to-fat ratio can flex based on personal preference and how your body responds, as long as neither drops too low. Keeping fat above 15 percent of total calories supports hormone production, and keeping carbs high enough supports training quality.
How to Track and Adjust
Weigh yourself at the same time each day (morning, after using the bathroom) and compare weekly averages rather than daily numbers. Water weight, meal timing, and digestive contents create fluctuations of 2 to 4 pounds on any given day, so a single weigh-in means very little.
If you’re gaining 0.5 to 1 pound per week as a beginner, or 0.5 to 0.75 pounds per week as an intermediate lifter, your surplus is in a productive range. If the scale isn’t moving after two to three weeks, add 100 to 200 more calories. If you’re gaining faster than 1 pound per week consistently, a significant portion is likely fat, and you should trim 100 to 200 calories.
Progress photos every two to four weeks and waist measurements are useful secondary checks. Your waist circumference rising quickly relative to your weight is a practical signal that fat is accumulating faster than muscle. The mirror often tells you more than the scale alone.
A Sample Approach for a 170-Pound Lifter
- Estimated TDEE: approximately 2,700 calories (training 4 days per week)
- Target surplus: 300 calories, bringing the daily total to 3,000
- Protein: 155 to 170 grams (spread across 4 to 5 meals)
- Carbohydrates: 400 to 430 grams
- Fat: 55 to 65 grams
- Expected weight gain: 2 to 4 pounds per month (beginner) or 1 to 2 pounds per month (intermediate)
Small snacks between main meals that include both a protein source and a carbohydrate source are an easy way to hit the surplus without forcing uncomfortably large meals. A Greek yogurt with fruit, a turkey sandwich, or a protein shake with a banana all work. The best strategy is whichever one you’ll actually stick to for months, because muscle growth is a slow process that rewards consistency far more than perfection on any single day.