How many calories do you need to build muscle?
In short
Eat a little more than you burn. Reviews suggest a surplus of about 10 to 20% above maintenance, with a weight gain of 0.25 to 0.5% of your body weight per week for beginners and intermediates. Experienced lifters should stay at the lower end. Start with an estimate, then let your weight trend tell you whether to eat more or less.
Cody de LeeuwLast checked 29 October 2026 · 7 min read
Step 1: find your maintenance
Maintenance is the amount you eat when your weight stays stable. There are two ways to find it:
- Estimate it. Formulas use your weight, height, age and sex to estimate how much you burn at rest, then multiply by how active you are. The Mifflin-St Jeor equation is the most used.1 A review found it the most reliable of the common formulas, but it still missed by more than 10% for some people.2
- Measure it. Log what you eat and weigh yourself for two to three weeks. If your weight stays flat, your average intake is your maintenance. If it moves, you can work out how far off you are.
An estimate is fine to start with. Your own data is better after a few weeks.
Step 2: pick a surplus
A review of nutrition for natural bodybuilders recommends eating about 10 to 20% above maintenance, aiming to gain 0.25 to 0.5% of your body weight per week. Experienced lifters should go slower, because they build muscle more slowly.3 Another review says the ideal surplus is unknown and advises starting conservatively.4
| Body weight | 0.25% per week | 0.5% per week |
|---|---|---|
| 60 kg | 0.15 kg | 0.3 kg |
| 75 kg | 0.19 kg | 0.38 kg |
| 90 kg | 0.23 kg | 0.45 kg |
That is slow on purpose. Gain faster and more of it tends to be fat.
A worked example
Say you weigh 75 kg and your maintenance is about 2,600 kcal:
- A 10% surplus is 260 kcal, so you eat about 2,860 kcal a day.
- Your target gain is 0.19 to 0.38 kg per week, or roughly 0.8 to 1.6 kg a month.
- Keep protein at about 1.6 to 2.2 g per kg: 120 to 165 g a day.
That extra 260 kcal is about one sandwich. Building muscle does not take huge meals.
Step 3: adjust from your trend
Day-to-day weight jumps up and down with water, salt and food in your gut. Look at the average over two to three weeks:
- Gaining faster than planned? Take off 100 to 200 kcal a day.
- Not gaining at all? Add 100 to 200 kcal a day.
- On track? Change nothing.
Make small changes and give each one two weeks before you judge it.
Can you build muscle without a surplus?
Sometimes. Beginners, people coming back after a break and people with more body fat can build muscle while their weight stays the same. Experienced, lean lifters usually need a surplus to keep gaining.4
Expert opinion evidence
No study has pinned down the best surplus for building muscle. The ranges here come from expert reviews that work from related research, and they ask you to start low and adjust. How we rate evidence
How Mitta does it
A target that learns from you.
Mitta starts with an estimate. With Pro, it then uses your own log and weight trend to find your real maintenance.
- Starts with Mifflin-St JeorYour first target uses your weight, height, age, sex and how many days you train.
- Then learns from your data (Pro)With Pro, after 10 logged days and 5 weigh-ins over about three weeks, Mitta estimates your maintenance from what you ate and how your weight moved.
- A careful surplusYour first target adds 250 kcal for building muscle. Once Pro knows your real maintenance, it aims about 7.5% above it, between 150 and 350 kcal a day. You can pick a slower or faster pace.
- Small stepsYour target moves by at most 200 kcal at a time, and never goes below a safe floor.
Eat enough to grow, without guessing.
Mitta sets your calorie target, shows the sum and adjusts it from your own trend. Free to start, in the web app for invited testers.
Questions about
How many calories do you need to build muscle
How many extra calories do I need to build muscle?
Reviews suggest about 10 to 20% above maintenance for beginners and intermediates, and less for experienced lifters. For most people that is a few hundred kcal a day.
How fast should I gain weight when bulking?
About 0.25 to 0.5% of your body weight per week for beginners and intermediates, and slower if you have trained for years.
Are calorie calculators accurate?
They are a good starting point. The Mifflin-St Jeor formula was the most reliable in a review of common formulas, but it still missed by more than 10% for some people. Your own log and weight trend are more accurate after a few weeks.
Can I build muscle while eating at maintenance?
Beginners, people returning after a break and people with more body fat often can. Lean, experienced lifters usually need a small surplus.
Do I need to count calories to build muscle?
No, but it helps you know whether you are actually in a surplus. Weighing yourself regularly and watching the trend is the minimum.
Sources
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990; 51(2): 241–247. doi.org/10.1093/ajcn/51.2.241
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association, 2005; 105(5): 775–789. doi.org/10.1016/j.jada.2005.02.005
- Iraki J, Fitschen P, Espinar S, Helms E. Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports, 2019; 7(7): 154. doi.org/10.3390/sports7070154
- Slater GJ, Dieter BP, Marsh DJ, Helms ER, Shaw G, Iraki J. Is an energy surplus required to maximize skeletal muscle hypertrophy associated with resistance training? Frontiers in Nutrition, 2019; 6: 131. doi.org/10.3389/fnut.2019.00131
Written by Cody de Leeuw. First published 29 October 2026, last checked 29 October 2026. This article is general information, not medical advice. Spotted a mistake? Tell me