Bulking Calorie Calculator
A bulking calorie calculator for lean gains. It computes your TDEE from the Mifflin-St Jeor equation, adds a controlled 10–20% surplus (your choice), and pairs it with a protein target from the ISSN 1.6–2.2 g/kg range — so the surplus builds muscle, not just waistline.
Result
| BMR (Mifflin-St Jeor) | |
| Activity multiplier | |
| Surplus | |
| Protein target |
Formula & source
Bulking target = TDEE × (1 + surplus%)
Protein = 1.6–2.2 g per kg body weight
Sources: Mifflin-St Jeor (1990) for TDEE; protein range from the ISSN position stand on protein and exercise (Jäger et al., 2017): 1.6–2.2 g/kg/day for building and maintaining muscle. The 10–20% surplus band is the standard lean-bulk practice — enough to grow, small enough that fat gain stays modest. Unique to this page: surplus and protein are solved together, not on separate tools.
Worked example (you can verify by hand)
Input: same male as TDEE example (TDEE 2763), 15% surplus, 81.65 kg.
- Target = 2763 × 1.15 = 3177.5
- Protein = 1.6×81.65 to 2.2×81.65 = 130.6 to 179.6 g
Expected output: ≈ 3178 kcal/day; protein 131–180 g/day.
Limitations — what this cannot do
- Equations estimate population averages — individual metabolism varies ±10–15%; treat output as a starting point and adjust from 2–3 weeks of scale and mirror data.
- Activity multipliers are the largest error source; be honest about training volume or the number is fiction.
- This is nutrition math, not medical advice — see the disclaimer below.
- A surplus only builds muscle with progressive training — extra calories without progressive overload mostly build fat.
Disclaimer: Estimates for training planning only, not medical advice. Consult a professional.
FAQ
How big a surplus for a lean bulk?
10–15% over TDEE for most lifters (roughly +250–400 kcal). Beginners and underweight lifters can push toward 20%; advanced lifters near their genetic ceiling should stay near 10%.
Will I gain fat while bulking?
Some — muscle synthesis is rate-limited, so part of any surplus becomes fat. The lean-bulk game is maximizing the muscle fraction: train hard, keep the surplus modest, sleep.
How much protein on a bulk?
1.6–2.2 g/kg/day per the ISSN position stand. More than ~2.2 g/kg shows no added muscle benefit in the research — spend the calories on carbs for training fuel instead.
How fast should scale weight rise?
Roughly 0.25–0.5% of body weight per week for intermediates. Faster than that and you are likely overshooting the surplus.