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Bulking calorie calculator
A lean bulk is a small, steady surplus that adds muscle with as little fat as possible. This calculator sets your calories from a weekly gain of 0.25 to 0.5% of your body weight, the pace research on lifters supports, then gives the protein, fat and carbs to match and the weeks to your goal.
Calculate your bulking calories
Calories a day to bulk at 0.25% a week
3,170kcal a day
That is 220 kcal over your estimated maintenance of 2,950, 7% more, for a gain of about 0.45 lb a week, or 1.8 lb over the first 4 weeks.
Protein, fat and carbs at 3,170 kcal
| Protein, the middle of 131 to 180 g | 156 g |
|---|---|
| Fat, 25% of calories | 88 g |
| Carbs, the rest | 439 g |
When to adjust
- Weigh yourself most mornings and compare weekly averages. Single days swing with water and food.
- The first week can jump, from water and stored carbohydrate as you eat more. Judge your pace from weeks 2 and 3.
- Gaining slower than 0.45 lb a week? Eat about 50 kcal a day more for each 0.1 lb a week you are short. Gaining faster? Eat that much less. Some people burn off much of a surplus through everyday movement (Levine et al., 1999), so trust the scale over the math.
- Run the numbers again every 4 weeks or so. A heavier body burns more, so the same intake gains more slowly over time.
Show the math
- Maintenance: 2,950 kcal, the NASEM 2023 estimate for your age, sex, height, weight and activity. The maintenance calculator shows the working and the likely range.
- Gaining 0.25% of your weight a week, at 7,700 kcal per kg: 81.65 kg × 0.25% × 7,700 ÷ 7 = 225 kcal a day, so 2,950 + 225 = 3,175, shown rounded to 3,170. The surplus is 7% of maintenance; the authors of a 2023 trial in trained lifters suggest 5 to 20% (Helms et al., 2023).
- Protein: 1.6 to 2.2 g per kg of body weight (Morton et al., 2018; Iraki et al., 2019): 81.65 kg × 1.6 to 2.2 = 131 to 180 g a day. The split uses the middle, 156 g.
- Fat: 25% of 3,170 kcal, which is 88 g at 9 kcal a gram.
- Carbs: 3,170 − 156 × 4 − 88 × 9 = 1,754 kcal, which is 439 g at 4 kcal a gram.
- 7,700 kcal per kg (3,500 per lb) is a planning number. What a kilo gained costs depends on how much of it is muscle and how much fat, and some people burn off part of any surplus by moving more (Levine et al., 1999). Your weekly average weight is the real test.
For adults 19 and over. Not for pregnancy or breastfeeding, or for anyone with a past or present eating disorder. General information, not medical advice.
How many calories should you eat to bulk?
Add about 11 kcal a day per kg of body weight for each 1% you want to gain a week. At 0.25% a week, the default here, an 82 kg (180 lb) man who maintains on 2,950 kcal eats about 3,170 kcal a day, and a 64 kg (140 lb) woman who maintains on 2,210 eats about 2,380. Research on lifters supports gaining 0.25 to 0.5% a week (Iraki et al., 2019).
At 0.5% a week he eats about 3,400 and she about 2,560. The sum is weight × pace × 7,700 kcal per kg ÷ 7 days. For him at 0.25%: 81.65 kg × 0.25% × 7,700 ÷ 7 = 224.5 kcal a day, and 2,950 + 224.5 = 3,174.5, rounded to 3,170.
That surplus is 7% of his maintenance: under the 10 to 20% one review suggests (Iraki et al., 2019), though inside the 5 to 20% the authors of a 2023 trial in trained lifters suggest (Helms et al., 2023). Both papers also give a weekly pace of 0.25 to 0.5% of body weight, and this calculator follows the pace because your scale can check it.
Both examples are 30 and low active, 5 ft 10 in and 5 ft 4 in tall, with maintenance from the NASEM 2023 equations (NASEM, 2023). The calculator above runs the same sum on your numbers, or on a maintenance you already know from your logs. The maintenance calorie calculator explains the estimate and how far off it can be.
How fast should you gain weight on a bulk?
Gain 0.25 to 0.5% of your body weight a week if you are new or intermediate, and stay at the slow end or below once you are advanced (Iraki et al., 2019; Helms et al., 2023). Gaining faster adds more fat without clearly adding more muscle: elite athletes who ate about 600 kcal a day more than a comparison group gained more fat, and their lean mass gains did not differ (Garthe et al., 2013).
| Training | Gain a week | At 82 kg | Over 4 weeks |
|---|---|---|---|
| New or intermediate | 0.25% to 0.5% | 0.2 kg (0.45 lb) to 0.41 kg (0.9 lb) | 0.82 kg (1.8 lb) to 1.63 kg (3.6 lb) |
| Advanced | 0.25% or less | 0.2 kg (0.45 lb) or less | 0.82 kg (1.8 lb) or less |
Newer lifters have the most room to grow, so the top of the range suits them best (Slater et al., 2019). If you have trained for years and your lifts now climb slowly, count yourself advanced: muscle comes slowly by then, and in trained lifters a bigger surplus added fat without clearly adding muscle (Helms et al., 2023).
Bulking calories by body weight
Your surplus grows with your weight: about 11 kcal a day per kg for each 1% a week. At 0.25% a week, that is about 170 kcal a day at 60 kg and 280 at 100 kg. Find your weight, then read across to your pace.
Men
| Weight | Maintenance | 0.25% a week | 0.5% a week |
|---|---|---|---|
| 60 kg (132 lb) | 2,630 | 2,800 | 2,960 |
| 65 kg (143 lb) | 2,700 | 2,880 | 3,060 |
| 70 kg (154 lb) | 2,780 | 2,970 | 3,170 |
| 75 kg (165 lb) | 2,850 | 3,060 | 3,260 |
| 80 kg (176 lb) | 2,930 | 3,150 | 3,370 |
| 85 kg (187 lb) | 3,000 | 3,230 | 3,470 |
| 90 kg (198 lb) | 3,080 | 3,330 | 3,580 |
| 95 kg (209 lb) | 3,150 | 3,410 | 3,670 |
| 100 kg (220 lb) | 3,230 | 3,510 | 3,780 |
| 105 kg (231 lb) | 3,300 | 3,590 | 3,880 |
| 110 kg (243 lb) | 3,380 | 3,680 | 3,990 |
Women
| Weight | Maintenance | 0.25% a week | 0.5% a week |
|---|---|---|---|
| 50 kg (110 lb) | 2,050 | 2,190 | 2,330 |
| 55 kg (121 lb) | 2,110 | 2,260 | 2,410 |
| 60 kg (132 lb) | 2,170 | 2,340 | 2,500 |
| 65 kg (143 lb) | 2,230 | 2,410 | 2,590 |
| 70 kg (154 lb) | 2,290 | 2,480 | 2,680 |
| 75 kg (165 lb) | 2,350 | 2,560 | 2,760 |
| 80 kg (176 lb) | 2,410 | 2,630 | 2,850 |
| 85 kg (187 lb) | 2,470 | 2,700 | 2,940 |
| 90 kg (198 lb) | 2,530 | 2,780 | 3,030 |
Taller, younger or more active than the tables? Your maintenance is higher, and so is your target: use the calculator above.
Lean bulk or dirty bulk?
A lean bulk. Eating far over maintenance adds fat without clearly building muscle faster. In elite athletes, a group eating about 600 kcal a day more than another raised its fat mass by 15% against 3%, and the lean mass gained did not differ between the groups (Garthe et al., 2013). Aim for 0.25 to 0.5% of your body weight a week instead.
A small 2023 trial in lifters with at least a year of training points the same way. The two surplus groups logged about 490 and 720 kcal a day over maintenance, yet both gained about 3.3 kg in 8 weeks, against 0.4 kg for a group at maintenance. Muscle thickness and squat strength did not differ between the groups, and the more weight a lifter gained, the more skinfold fat they added (Helms et al., 2023). Bench press rose most in the larger-surplus group, by 13.4 kg against 7.3 and 5.7 kg: in a trial this small, a hint rather than proof.
Do you need a calorie surplus to build muscle?
Not strictly. Lifters can gain muscle at maintenance or even in a small deficit, and a review found many studies of trained lifters gaining muscle while losing fat (Barakat et al., 2020). How big a surplus muscle growth needs is not known; one review suggests starting at about 360 to 480 kcal a day and adjusting from there (Slater et al., 2019).
A surplus is the simple way to make sure you gain, which matters most for lifters who are lean already. If you carry more fat, eating near maintenance while you train hard can work better: check whether to cut or bulk.
Protein, carbs and fat on a bulk
Eat 1.6 to 2.2 g of protein per kg of body weight a day. In a meta-analysis of 49 trials, extra protein stopped adding lean mass from training at about 1.6 g per kg, with 2.2 at the top of the likely range (Morton et al., 2018). Keep fat at 20% of calories or more (Thomas et al., 2016); this calculator uses 25%, and carbs fill the rest.
| Macro | Rule | A day |
|---|---|---|
| Protein | The middle of 1.6 to 2.2 g per kg, which is 131 to 180 g | 156 g |
| Fat | 25% of calories, at 9 kcal a gram | 88 g |
| Carbs | The rest, at 4 kcal a gram | 439 g |
A review of bulking for physique athletes suggests 3 to 5 g of carbs per kg a day or more, and 0.5 to 1.5 g of fat (Iraki et al., 2019). For him that is 245 to 408 g of carbs or more, and 41 to 122 g of fat, so the split above fits.
Why you aren’t gaining weight on a bulk
Most often your maintenance is higher than the estimate, or you move more as you eat more. When 16 adults ate 1,000 kcal a day over their needs for 8 weeks, fat gain varied 10-fold between them, and about two-thirds of the extra burn came from everyday movement rather than exercise (Levine et al., 1999).
- The estimate. For about 1 in 3 people, true maintenance sits more than 340 kcal (men) or 250 kcal (women) from the calculated number (NASEM, 2023).
- Everyday movement. In the same study, the people whose everyday movement rose most stored the least fat (Levine et al., 1999).
- Water first. Eating more carbohydrate refills its stores, and stored carbohydrate holds three to four parts water (Kreitzman et al., 1992), so the first week can jump. Judge your pace from weeks 2 and 3.
Compare weekly averages. If you are gaining more slowly than planned, eat about 110 kcal a day more for each 0.1 kg a week you are short (50 for each 0.1 lb).
How long should a bulk last?
Until you reach your goal weight, or your waist reaches half your height, which NICE advises staying under (NICE, 2025). Gaining 5% of your body weight takes about 20 weeks at 0.25% a week and 10 at 0.5%, re-running the numbers every few weeks as you get heavier.
| Gain | 0.25% a week | 0.5% a week |
|---|---|---|
| 2.5% (2 kg at 80 kg) | 10 weeks | 5 weeks |
| 5% (4 kg at 80 kg) | 20 weeks | 10 weeks |
| 10% (8 kg at 80 kg) | 38 weeks | 19 weeks |
Measure your waist every few weeks along with your weight. If it nears half your height, end the bulk: the cut or bulk check and the cutting calculator take it from there.
Questions
How much weight should I gain a month on a bulk?
About 1 to 2% of your body weight: 0.25 to 0.5% a week for 4 weeks. For an 82 kg (180 lb) lifter, that is 0.8 to 1.6 kg (1.8 to 3.6 lb) a month. Newer lifters can aim for the top of that range; advanced lifters should stay at the bottom or below (Iraki et al., 2019).
Is a 500 calorie surplus too much?
For most lifters it is more than the pace research supports. By the 3,500-calorie rule, 500 kcal a day is about 0.45 kg (1 lb) a week, which is 0.5% of body weight only at about 91 kg (200 lb). Anyone lighter would gain faster than the 0.25 to 0.5% a week a review suggests (Iraki et al., 2019), and in elite athletes, gaining faster added fat but no more lean mass (Garthe et al., 2013).
Can you bulk without gaining fat?
Not entirely. By Forbes’s model, the share of a gain that is lean mass shrinks as body fat rises: about 51% at 10 kg of fat and 34% at 20 kg (Chow and Hall, 2008). The model was fitted in people who were not lifting, so treat those numbers as a guide. Gaining slowly while you train hard keeps the fat down: in trained lifters, those who gained more weight added more skinfold fat (Helms et al., 2023).
Do I need 1 g of protein per pound to bulk?
No. 1 g per lb is 2.2 g per kg, the top of the 1.6 to 2.2 g per kg range. In a meta-analysis, extra protein stopped adding lean mass from training at about 1.6 g per kg (Morton et al., 2018), so 1 g per lb is a generous, simple target rather than a requirement.
Should beginners bulk?
They can. Newer lifters have the most room to grow (Slater et al., 2019), so the top of the 0.25 to 0.5% a week range suits them (Iraki et al., 2019). Beginners can also gain muscle while losing fat, so a bulk is not the only way (Barakat et al., 2020). If your waist is half your height or more, a level NICE links to increased health risk (NICE, 2025), lose fat first: the cut or bulk check on this site makes the call from your numbers.
Who should not use this calculator?
It is built for adults 19 and over. It is not for pregnancy or breastfeeding, for anyone with a past or present eating disorder, or for anyone with a medical condition that affects weight or appetite. It is general information, not medical advice: in those situations, ask a doctor or registered dietitian.
Sources
- Barakat C, Pearson J, Escalante G, Campbell B, De Souza EO (2020). Body recomposition: can trained individuals build muscle and lose fat at the same time?. Strength and Conditioning Journal 42(5):7-21. doi:10.1519/SSC.0000000000000584
- Chow CC, Hall KD (2008). The dynamics of human body weight change. PLoS Computational Biology 4(3):e1000045. doi:10.1371/journal.pcbi.1000045
- Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen J (2013). Effect of nutritional intervention on body composition and performance in elite athletes. European Journal of Sport Science 13(3):295-303. doi:10.1080/17461391.2011.643923
- Helms ER, Spence AJ, Sousa C, et al. (2023). Effect of small and large energy surpluses on strength, muscle, and skinfold thickness in resistance-trained individuals: a parallel groups design. Sports Medicine - Open 9:102. doi:10.1186/s40798-023-00651-y
- Iraki J, Fitschen P, Espinar S, Helms E (2019). Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports 7(7):154. doi:10.3390/sports7070154
- Kreitzman SN, Coxon AY, Szaz KF (1992). Glycogen storage: illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition. American Journal of Clinical Nutrition 56(1 Suppl):292S-293S. doi:10.1093/ajcn/56.1.292S
- Levine JA, Eberhardt NL, Jensen MD (1999). Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science 283(5399):212-214. doi:10.1126/science.283.5399.212
- Morton RW, Murphy KT, McKellar SR, et al. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine 52(6):376-384. doi:10.1136/bjsports-2017-097608
- National Academies of Sciences, Engineering, and Medicine (2023). Dietary Reference Intakes for Energy. Washington, DC: The National Academies Press. doi:10.17226/26818
- National Institute for Health and Care Excellence (2025). Overweight and obesity management. NICE guideline NG246, last updated 8 January 2026. nice.org.uk/guidance/ng246
- Slater GJ, Dieter BP, Marsh DJ, et al. (2019). Is an energy surplus required to maximize skeletal muscle hypertrophy associated with resistance training. Frontiers in Nutrition 6:131. doi:10.3389/fnut.2019.00131
- Thomas DT, Erdman KA, Burke LM (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics 116(3):501-528. doi:10.1016/j.jand.2015.12.006
Each figure quoted from a study was checked against the paper, or its abstract where the full text could not be read. Found an error? Email founder@topsets.app and the page will be corrected and its date updated.