What is a realistic monthly gain for lean bulk?
0.4–1.2% of bodyweight, depending on training experience. The calculator returns your band.
Muscle Gain Calculator a lean bulk
a lean bulk only works at a calorie position the body can convert into muscle, not fat. This page sets a daily surplus, protein anchor and monthly gain target for lean bulk that the research supports — small enough to stay lean, large enough that training adapts.
The right pace for a lean bulk
Lean gain runs at 0.4–1.2% of bodyweight per month depending on training history. The calculator scales the surplus to match — 250–400 kcal/day, no more — because anything above that band lands as fat regardless of training quality.
Aggressive bulks feel productive in week 2. By week 8 they require a long cut that erases the lean gains alongside the fat.
Protein, training and recovery for a lean bulk
Protein at 1.8 g/kg, training that progressively overloads the main lifts, sleep that supports recovery — those three together make the surplus into muscle. Without all three, extra calories are just storage.
Track strength on key lifts week to week. If they move, the plan works; if they plateau for 3+ weeks at the same bodyweight, technique or recovery is the bottleneck — not calories.
How AJYX manages a lean bulk
Inside AJYX, calories adjust as the weight trend responds. lean bulk stay inside the lean-gain band without recalculating manually — the app trims when gain runs hot and nudges up when it stalls.
Use this page as the standalone read. Move into the app for a lean bulk run on autopilot.
FAQ
Should lean bulk eat more than the calculator says?
Only if monthly gain falls below the lower end of the band for 3+ weeks. Otherwise extra calories are fat, not muscle.
How long should a lean bulk last?
8–16 weeks of focused gain followed by a short maintenance or mini-cut. Continuous bulks past 16 weeks see fat outpace muscle as the ratio worsens.