How fast can muscle gain reasonably run muscle gain?
0.5–1% of bodyweight per week is the sweet spot. The calculator picks within that band and protects lean mass by capping the deficit.
Most fat-loss calculators sell speed. muscle gain reward the opposite: a deficit you can hold for months, not a sprint that collapses by week six. This page builds a daily calorie target and timeline for muscle gain around what research actually supports — a 20% deficit, capped, floored, and stretched by a 10% buffer because real life is messier than the math.
Fast fat loss costs lean mass and adherence. muscle gain progress fastest when the weekly rate sits at 0.5–1% of bodyweight — fast enough to feel the trend, slow enough to keep training and recovery intact.
Anyone can lose weight for a fortnight. muscle gain who finish muscle gain were running a deficit they could still hit on month three.
TDEE comes from Mifflin-St Jeor plus activity. The deficit is set at 20%, clamped between 300 and 750 kcal/day, and the daily target is floored at 1200 (women) / 1400 (men). muscle gain respects health markers — no aggressive starvation defaults.
Weeks-to-goal multiplies the math by 1.10 to account for adaptation. Treat the timeline as honest, not optimistic.
Inside AJYX, your fat-loss plan adapts as the weight trend responds — the app rebalances calories before plateaus and integrates training so lean mass holds throughout muscle gain.
Use this page as the standalone read. Move into the app once you want muscle gain managed instead of recalculated.
0.5–1% of bodyweight per week is the sweet spot. The calculator picks within that band and protects lean mass by capping the deficit.
Short windows (4–6 weeks) of a 25–30% deficit are workable with rigorous recovery and high protein. As a default, no — adherence drops more than the deficit gains.
First check actual adherence over the past 2 weeks (it is usually the answer). If real, drop calories by 100–150/day or add 1–2 strength sessions before cutting further.