Bulking Calorie Calculator
A bulking calorie calculator for lean gains. It estimates TDEE from the Mifflin-St Jeor equation and an activity multiplier, applies your chosen surplus, and displays the site’s 1.6–2.2 g/kg protein planning range.
Result
| Estimated TDEE | |
| 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
Method and assumptions: Mifflin-St Jeor (1990) estimates resting energy use; this site applies a selected activity multiplier as a modeling assumption for TDEE. The combined estimate does not establish an individual accuracy range. The surplus percentage is your planning input, not a prediction of muscle gain. The site uses 1.6–2.2 g/kg/day as a planning assumption. The ISSN 2017 position stand describes 1.4–2.0 g/kg/day for most exercising people and discusses higher intakes in specific training or energy-restriction contexts. Individual needs vary.
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
- This is a planning estimate, not a measurement of your energy use. Resting-energy equations and selected activity factors do not establish a fixed personal error range; review the estimate against your own trend and circumstances.
- 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?
The site uses 1.6–2.2 g/kg/day as a planning assumption. The ISSN 2017 position stand describes 1.4–2.0 g/kg/day for most exercising people and discusses higher intakes in specific training or energy-restriction contexts. Individual needs vary.
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.