On a lean bulk you should gain 0.25 to 0.5 percent of your body weight per week. At 70 kg that is 0.18 to 0.35 kg, at 80 kg 0.2 to 0.4 kg and at 90 kg 0.23 to 0.45 kg a week (roughly 0.4 to 1 lb). A good starting point is the middle at 0.35 percent, about 0.28 kg a week at 80 kg. That takes a surplus of roughly 300 kcal a day. Whether you hit that pace is shown by your trend weight after two to three weeks, not by the scale on any given morning.
The range comes from a review on bodybuilding nutrition in the off-season (Iraki et al. 2019). This article shows how to turn it into a concrete number of kilos per week and how to check it.
Table: kg per week by body weight
The "surplus" column applies to the midpoint of 0.35 percent. It uses the approximation of about 7,700 kcal per kilo of body weight (Hall 2008), which works out at roughly 110 kcal a day for every 0.1 kg per week.
| Body weight |
Range per week (0.25 to 0.5%) |
Midpoint (0.35%) |
Surplus per day (approx.) |
| 60 kg |
0.15 to 0.30 kg |
0.21 kg |
230 kcal |
| 65 kg |
0.16 to 0.33 kg |
0.23 kg |
250 kcal |
| 70 kg |
0.18 to 0.35 kg |
0.25 kg |
270 kcal |
| 75 kg |
0.19 to 0.38 kg |
0.26 kg |
290 kcal |
| 80 kg |
0.20 to 0.40 kg |
0.28 kg |
310 kcal |
| 85 kg |
0.21 to 0.43 kg |
0.30 kg |
330 kcal |
| 90 kg |
0.23 to 0.45 kg |
0.32 kg |
350 kcal |
| 95 kg |
0.24 to 0.48 kg |
0.33 kg |
370 kcal |
| 100 kg |
0.25 to 0.50 kg |
0.35 kg |
390 kcal |
The kcal values are starting points, not a guarantee. How much surplus you really need depends on your expenditure, and that is only an estimate until your trend confirms it.
Where you should land within the range depends mainly on your training experience. Iraki et al. place beginners nearer the top and experienced lifters around 0.25 percent. If you carry a lot of body fat, a fast bulk pays off even less. Whether a bulk is the right next step for you at all can be checked with the FFMI calculator.
Why not more than 0.5 percent?
Because gaining faster mainly means gaining fat faster. Two studies show this very directly:
- In a study with elite athletes, the group eating more gained 3.9 percent of body weight over 8 to 12 weeks, the comparison group 1.5 percent. Lean mass rose equally in both groups, but fat mass rose by 15 instead of 3 percent (Garthe et al. 2013).
- In an eight-week study with resistance-trained participants, faster weight gain mainly predicted larger increases in skinfold thickness. Muscle thickness barely benefited (Helms et al. 2023).
Every extra kilo of fat you put on during a bulk has to come off in a later cut. At a cutting pace of 0.5 to 0.6 kg a week, one kilo too many costs you almost two weeks of dieting.
What the scale shows week by week
A plan of 0.28 kg a week does not mean the scale shows 0.28 kg more every Monday. In practice a lean bulk tends to look like this:
| Period |
What you see on the scale |
What is behind it |
| Weeks 1 to 2 |
Often clearly more than planned |
Glycogen stores fill with water, more food in transit |
| From week 3 |
Trend moves towards plan |
The surplus shows as real gain |
| Every week |
Morning readings jump by 1 to 2 kg |
Water, salt, carbs, training |
Glycogen explains the early jump: each gram is stored with roughly three to four grams of water (Kreitzman et al. 1992). Cutting calories after week one corrects water and leaves you below plan afterwards. More on this effect after hard sessions is in Weight up after training on a bulk.
How to check your pace in kg per week
- Weigh every morning under the same conditions. The details are in How to track your weight on a bulk.
- Build a trend weight, for example a 14 day average or exponential smoothing. How that works is shown in Weight moving average for bulking and cutting.
- From week three, read the weekly rate: trend today minus trend seven days ago. The number gets calmer if you take the change over 14 days and divide by two.
- Compare it with your range. If the rate falls within your row of the table, you are on track.
If you would rather not calculate yourself, paste your morning readings into the weight trend calculator. It shows trend and weekly rate.
Too slow or too fast: how to correct
You can convert the deviation in kg per week straight into kcal: deviation times 1,100 gives the change per day.
- Too slow, example: target 0.28 kg, measured 0.10 kg a week over three weeks. The gap of 0.18 kg equals about 200 kcal more per day.
- Too fast, example: target 0.28 kg, measured 0.50 kg a week from week three. The difference of 0.22 kg equals about 240 kcal less per day.
After every change, measure for another two to three weeks before adjusting again. How big your surplus should be at the start is covered in detail in Lean bulk calories; work out your starting point in the bulk and cut calorie calculator.
One more detail for long bulks: as you get heavier, your target in kg per week grows slightly too. Every four to six weeks it is worth looking at the table again with your new trend weight.
More on gaining is collected in the Build muscle section.
FAQ
How many kg per month is normal on a lean bulk?
At 80 kg and 0.25 to 0.5 percent a week, about 0.9 to 1.7 kg a month. The first week can add clearly more because of glycogen and water.
Is 0.5 kg per week too much?
At 100 kg, 0.5 kg sits exactly at the upper limit of 0.5 percent. At 70 kg it would be just over 0.7 percent a week and probably more fat than necessary.
What if I am not gaining at all?
Then your surplus is not really a surplus. Usually expenditure is higher than estimated or intake lower than you think. After two to three weeks without gain, add 150 to 200 kcal a day.
Does the table apply to women too?
Yes, the percentages scale with body weight. With cycle-related fluctuations it helps to compare the same cycle phases before judging the rate.
Sources
- Iraki J, Fitschen P, Espinar S, Helms E. Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review. Sports (Basel). 2019;7(7):154. PubMed
- Hall KD. What is the required energy deficit per unit weight loss? Int J Obes (Lond). 2008;32(3):573-576. PubMed
- Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen J. Effect of nutritional intervention on body composition and performance in elite athletes. Eur J Sport Sci. 2013;13(3):295-303. PubMed
- Helms ER, Spence AJ, Sousa C, et al. Effect of Small and Large Energy Surpluses on Strength, Muscle, and Skinfold Thickness in Resistance-Trained Individuals: A Parallel Groups Design. Sports Med Open. 2023;9(1):102. PubMed
- Kreitzman SN, Coxon AY, Szaz KF. Glycogen storage: illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition. Am J Clin Nutr. 1992;56(1 Suppl):292S-293S. PubMed
