Bulking Calorie Calculator: Lean Bulk Calories Per Day
Bulking calorie calculator: how many calories to eat a day to bulk, sized to your training age for a lean bulk, plus how to split them into macros.
Eating enough and still not growing? Find the real bottleneck.
Beginners sit at the top of both ranges: a 20% surplus and about 0.5% of bodyweight a week. These are estimates: weigh yourself often and adjust intake if the scale trend runs clearly faster or slower than the monthly figure.
BMR by Mifflin–St Jeor. Activity factor from the FAO/WHO/UNU worked examples (1.53 mostly sitting, 1.76 moderately active, 2.25 very active). A gain of 0.25–0.5% of bodyweight a week from Iraki et al., who advise larger surpluses for newer lifters and the low end for advanced ones; in trained lifters a 15% surplus added fat without more muscle than 5% (Helms et al. 2023), so intermediates start at 10% and advanced lifters at 5%.
Sources: Mifflin et al. 1990, Am J Clin Nutr; FAO/WHO/UNU Human Energy Requirements, ch. 5; Iraki et al. 2019, Sports 7(7):154; Helms et al. 2023, Sports Med Open — 5% vs 15% surplus in trained lifters.
Numbers not moving for weeks? Find out why- Updated
- Reading time
- 4 min
- By
- LiftDecode
To bulk, eat your maintenance calories plus 5–20%: about 20% if you are new to lifting, 10% after a year or two and 5% if you are advanced. This calculator estimates both numbers and how fast the scale should rise; a lean bulk keeps the gain to 0.25–0.5% of bodyweight a week. After two weeks, your scale trend is the better calculator.
How do you use the bulking calorie calculator?
Enter your sex, age, height, weight, daily activity outside the gym and training experience. You get a daily calorie target, the full surplus range and the monthly weight gain to expect.
- Pick activity for your normal day, not your best one; overestimating it is the most common reason a bulk turns into a fat gain.
- Weigh yourself every morning and compare weekly averages with the target.
How does it estimate your maintenance calories?
It multiplies your resting energy from the Mifflin-St Jeor equation by an activity factor: 1.53 if you mostly sit, 1.76 if moderately active, 2.25 if very active, the worked examples in the FAO/WHO/UNU energy report (FAO/WHO/UNU).
Mifflin-St Jeor predicted resting energy within 10% of measured values for more people than other common equations (Frankenfield et al., 2005). It is less reliable for very muscular lifters: in physique athletes, most equations underestimated resting metabolism (Tinsley et al., 2019). If you are heavily muscled, expect to need a little more than the estimate.
How big should your calorie surplus be?
Smaller than most people think, and smaller the longer you have trained. Beginners can use about 20% above maintenance; trained lifters gain little extra muscle from more than 5–10%.
| Training age | Surplus | Weight gain per week | 28-year-old man, 165 lb, desk job |
|---|---|---|---|
| Beginner | 20% | about 0.5% of bodyweight | 3,170 kcal |
| Intermediate | 10% | about 0.35% | 2,900 kcal |
| Advanced | 5% | about 0.25% | 2,770 kcal |
The weekly gain range of 0.25–0.5% of bodyweight comes from a review of off-season bodybuilding nutrition (Iraki et al., 2019). The low surpluses for trained lifters come from a trial in 17 of them: a 15% surplus added more skinfold fat than eating at maintenance, with no evidence of more muscle than a 5% surplus (Helms et al., 2023).
How fast should the scale move on a bulk?
About 0.25–0.5% of bodyweight a week, the range the off-season review recommends (Iraki et al., 2019). For a 165 lb lifter that is roughly 0.4–0.8 lb a week, or 1.8–3.6 lb a month. Faster than that is mostly fat; slower usually means you are eating less than you think. Check your actual rate with the calorie surplus check.
What macros should you eat on a bulk?
Protein first, fat moderate, carbohydrate for the rest. An off-season review recommends 1.6–2.2 g of protein per kg a day, 0.5–1.5 g of fat per kg and at least 3–5 g of carbohydrate per kg (Iraki et al., 2019). For the 165 lb (75 kg) intermediate above at 2,900 kcal: 135 g protein, 75 g fat and about 420 g carbs. The macro calculator for muscle gain works it out for you.
What if you're gaining weight but not muscle or strength?
Then food is not your bottleneck. If the scale is rising on schedule and your lifts and measurements are not, the cause is in training or recovery: sets that stop too early, no progression, too little volume or short sleep. Find out which one is yours before you eat more.
FAQ
How many calories should I eat to bulk?
Your maintenance plus 5–20%, depending on training age. For a 2,640 kcal maintenance that is 2,770–3,170 kcal. Start at the level the calculator gives you and adjust by 100–200 kcal after two weeks of weigh-ins.
Will I gain muscle if I eat 3,000 calories a day?
Only if 3,000 is above your maintenance and you train hard. For a small, sedentary lifter it is a solid surplus; for a big, active one it may be maintenance or below.
What is the difference between a lean bulk and a clean bulk?
A lean bulk is about the size of the surplus: small enough that the scale rises 0.25–0.5% a week (Iraki et al., 2019). A clean bulk is about food quality. You can eat clean and still overshoot, so watch the rate.
Is a dirty bulk faster?
Faster on the scale, not in muscle. In 17 trained lifters, a 15% surplus added more skinfold fat than maintenance and no clear extra muscle over 5% (Helms et al., 2023).
Written and maintained by LiftDecode. Training and nutrition education for healthy adults, not medical advice — if you have a health condition or an injury, talk to a professional who can examine you.