Build muscle, stay lean
Lean Bulk Calculator
Find the calories and macros for a lean bulk: a small surplus that builds muscle while keeping fat gain low. Get your daily target, compare a few surplus sizes, and see an honest verdict on how fast you should really be gaining.
Your lean bulk plan
Lean bulk calories & macros
Target calories
2,982kcal/day
- Maintenance
- 2,710 kcal
- Daily surplus
- +271 kcal
- about 10% over maintenance
- Suggested weekly gain
- 0.4–0.9 lb
- 0.25–0.5% of bodyweight
Daily macros
- Protein
- 144 g
- 575 kcal · 19%
- Carbs
- 440 g
- 1,760 kcal · 59%
- Fat
- 72 g
- 647 kcal · 22%
A lean bulk works best as a small, patient surplus, aimed at roughly 0.25 to 0.5% of your bodyweight gained per week. How much of that new weight is muscle rather than fat depends on your training, sleep and how new you are to lifting, and cannot be predicted exactly: beginners keep the ratio high, while advanced lifters gain more slowly. Weigh in over 2 to 4 weeks and trim the surplus if the scale climbs faster than the range above.
Compare your options
Compare surplus scenarios side by side
A bigger surplus is not a faster shortcut to muscle: past a point it just adds fat. See the target calories, weekly surplus and a rough weekly gain for a +200, +300 and +400 kcal surplus at once, with each one tagged for how lean the pace is likely to be.
Units
Maintenance ≈ 2,710 kcal/day · lean pace ≈ 0.4–0.9 lb/week
+200 kcal/day
Target calories
2,910 kcal
- Weekly surplus
- ≈ 1,400 kcal
- Rough weekly gain
- ≈ 0.4 lb
- Pace
- Conservative
+300 kcal/day
BalancedTarget calories
3,010 kcal
- Weekly surplus
- ≈ 2,100 kcal
- Rough weekly gain
- ≈ 0.6 lb
- Pace
- Lean
+400 kcal/day
Target calories
3,110 kcal
- Weekly surplus
- ≈ 2,800 kcal
- Rough weekly gain
- ≈ 0.8 lb
- Pace
- Lean
Each weekly gain is a rough energy estimate (about 7,700 kcal per kilo, near 3,500 kcal per pound). Real gain is often a little slower, and how much is muscle rather than fat depends on your training and how new you are to lifting: it cannot be predicted exactly. Aim for the surplus tagged Lean, and trim calories if the scale climbs faster than 0.4 to 0.9 lb per week.
What is a lean bulk?
A lean bulk is a muscle-building phase run on a small calorie surplus, usually about 10 to 20% above your maintenance calories. The idea is simple: give your body just enough extra energy to build muscle, without the pile of fat that comes with an aggressive "dirty" bulk. You gain more slowly, but far more of the mirror progress is muscle, and you spend less time cutting afterwards.
It is the opposite trade-off to a calorie deficit, where you eat under maintenance to lose fat. If you are new to lifting or carrying more body fat, a body recomposition around maintenance can build muscle and lose fat at once instead.
How this lean bulk calculator works
First we estimate your maintenance calories (your TDEE). We calculate your basal metabolic rate with the Mifflin-St Jeor equation, or the more precise Katch-McArdle equation if you enter your body fat %, then multiply it by an activity factor. We then add about a 10% surplus to set your lean bulk calories and split them into protein, carbs and fat.
The side-by-side tool higher up lets you compare a +200, +300 and +400 kcal surplus. For each one it shows your target calories, the weekly surplus, and a rough weekly weight gain, computed from energy alone. The table below shows those same rough gains at a glance.
| Daily surplus | ≈ per week | Rough weekly gain |
|---|---|---|
| +200 kcal/day | 1,400 kcal | 0.18 kg (0.40 lb) |
| +300 kcal/day | 2,100 kcal | 0.27 kg (0.60 lb) |
| +400 kcal/day | 2,800 kcal | 0.36 kg (0.80 lb) |
How fast should you gain on a lean bulk?
Aim to gain roughly 0.25 to 0.5% of your bodyweight per week. That is fast enough to support muscle growth, but slow enough that most of the new weight is not fat. Beginners can sit at the top of that range and even a touch above; the more advanced and lean you are, the slower you should go, because muscle comes harder and extra calories increasingly become fat.
The table below turns that pace into concrete weekly numbers for a few bodyweights. Weigh yourself a few mornings a week, follow the trend over two to four weeks, and if you are gaining faster than this, trim your surplus.
| Bodyweight | Slow (0.25%/wk) | Faster (0.5%/wk) |
|---|---|---|
| 60 kg (132 lb) | 0.15 kg (0.3 lb) | 0.30 kg (0.7 lb) |
| 75 kg (165 lb) | 0.19 kg (0.4 lb) | 0.38 kg (0.8 lb) |
| 90 kg (198 lb) | 0.23 kg (0.5 lb) | 0.45 kg (1.0 lb) |
Lean bulk macros: protein, carbs and fat
Protein is the priority: aim for about 1.6 to 2.2 g per kg of bodyweight per day (this tool uses roughly 1.8 g per kg for a lean bulk). Protein is the raw material for muscle, but it is the training stimulus and eating enough total calories that actually drive growth. Keep fat at a healthy minimum, around 0.9 g per kg, and put most of the surplus into carbohydrates to fuel hard training and recovery. The macro calculator and protein intake calculator can fine-tune these.
Clean bulk vs dirty bulk
A dirty bulk means eating in a large surplus with little regard for how much fat you add, on the theory that more calories equal more muscle. In practice, once your protein and training are in place, a bigger surplus mostly adds fat, not muscle. A lean or "clean" bulk keeps the surplus modest and the food quality high, so you finish the phase lean enough to keep going rather than needing a long cut.
How much muscle can you really build?
Honestly, less than most calculators suggest, and the exact muscle-to-fat split of new weight cannot be predicted. It depends on your training age, effort, sleep and genetics. Beginners keep a high share of new weight as muscle; advanced lifters gain muscle slowly and risk adding more fat from the same surplus. Treat any single muscle-versus-fat figure as a rough guide, not a promise, and judge progress by strength, the mirror and the scale trend together.
Good to know
Frequently asked questions
What is a lean bulk?
A lean bulk means eating a small calorie surplus, usually about 10 to 20% above your maintenance calories, so you gain muscle while keeping fat gain to a minimum. It trades a slower rate of weight gain for a leaner result than an aggressive 'dirty' bulk, which piles on extra fat you later have to diet off.
How many calories should I eat to lean bulk?
Start from your maintenance calories (your TDEE) and add a modest surplus. This calculator uses about 10% over maintenance by default, and the surplus tool lets you compare a +200, +300 and +400 kcal/day surplus side by side. For most people that lands somewhere between 200 and 400 extra calories a day.
How big should my calorie surplus be?
A surplus of roughly 200 to 400 kcal/day (about 10 to 20% over maintenance) is the usual sweet spot. Larger surpluses do not build muscle any faster once your training and protein are in place: past a point, the extra calories mostly become body fat. Bigger is not better here.
How fast should I gain weight on a lean bulk?
A common, sustainable target is about 0.25 to 0.5% of your bodyweight per week. For an 80 kg (176 lb) lifter that is roughly 0.2 to 0.4 kg (0.4 to 0.9 lb) a week. Beginners can sit at the top of that range; advanced lifters should aim lower. If the scale climbs faster, trim your surplus.
What are the best macros for a lean bulk?
Keep protein around 1.6 to 2.0 g per kg of bodyweight to build muscle, set fat at a healthy minimum (roughly 0.9 g per kg), and put most of the surplus into carbohydrates to fuel training and recovery. This calculator splits your target calories into protein, carbs and fat automatically.
How much protein do I need to build muscle?
Around 1.6 to 2.2 g of protein per kg of bodyweight per day covers nearly everyone who lifts, and going much higher does not add more muscle. Protein is the raw material; the training stimulus and eating enough total calories are what actually drive growth. This tool leans toward roughly 1.8 g per kg for a lean bulk.
How much muscle can I actually build?
Honestly, less than most calculators imply, and the split between muscle and fat on new weight cannot be predicted precisely. It depends on your training age, effort, sleep and genetics. Beginners keep a high share of new weight as muscle; the more advanced you are, the slower muscle comes and the more a surplus risks adding fat. Treat any muscle-versus-fat figure as a rough guide, not a promise.
Is a clean bulk the same as a lean bulk?
Broadly, yes. 'Clean bulk' usually emphasises the food quality (whole, minimally processed foods) while 'lean bulk' emphasises the small surplus that limits fat gain. In practice people use the terms interchangeably: a modest surplus, high protein, and mostly nutritious food.
How long should a lean bulk last?
Most people run a lean bulk for a few months at a time, long enough to make visible progress, then hold at maintenance or take a short cut if fat creeps up. Judge it by the mirror, the scale trend, and strength in the gym rather than a fixed calendar. Muscle is built over months, not weeks.
Should I lean bulk or do a body recomposition?
If you are a beginner or carrying higher body fat, a body recomposition around maintenance can build muscle and lose fat at once. If you are already fairly lean and want to add size faster, a lean bulk in a small surplus is usually more effective. Our body recomposition calculator can help you compare the two.
Is this medical or nutritional advice?
No. This calculator is for general information and education only and is not medical or nutritional advice. Consult a qualified professional before changing your diet or training, especially if you have a medical condition.
Evidence
Sources & references
- Mifflin MD, St Jeor ST, et al. (1990). A new predictive equation for resting energy expenditure · The BMR equation this calculator uses by default to estimate your maintenance calories.
- Jäger R, et al. (2017). ISSN Position Stand: Protein and Exercise · International consensus that people who train need protein well above the RDA to build and keep muscle.
- Morton RW, et al. (2018). Protein supplementation and resistance training: a systematic review and meta-analysis · Points to about 1.6 g/kg as the intake beyond which extra protein adds little muscle, the lower end of the range used here.
- Iraki J, Fitschen P, Espinar S, Helms E (2019). Nutrition Recommendations for Bodybuilders in the Off-Season · Peer-reviewed support for a modest surplus and a ~0.25 to 0.5% bodyweight gain per week.
Keep going