Lean surplus · Free

TDEE Calculator for Muscle Gain

Muscle grows best in a small surplus — not a dirty bulk. This page finds maintenance first, then adds a controlled surplus so most of the gain is tissue, not just scale weight.

+200–300
kcal/day lean surplus
0.25–0.5%
body weight gain / week
1.6–2.2 g
protein per kg
2–4 kg
realistic yearly muscle for intermediates

Your stats

Standard inputs first — the age adjustment is applied below.

Biological sex
yrs
lb
Height
ft
in
%

Surplus size

Newer lifters can use a slightly larger surplus. Advanced lifters stay closer to maintenance.

−-8%
Training stage

About a +200–300 kcal surplus — the usual lean-gain target.

Estimates are typically within ±10%. Track your weight for two weeks and adjust by 100–200 kcal.

The context

Muscle-gain TDEE is maintenance plus a little

You cannot force-feed muscle. Extra calories beyond what training can use become fat. A lean surplus sits just above TDEE so recovery and progressive overload have fuel without a rapid waistline change.

If the scale climbs faster than about 0.5% of body weight per week for months, shrink the surplus. If lifts stall and the scale is flat for three weeks, nudge up 100–150 kcal.

Why the formula drifts

What actually drives muscle gain

Calories help. These decide whether they become muscle.

01

Progressive overload

If week-to-week load or reps are not climbing, the surplus has nowhere to go.

02

Protein distribution

Hit ~1.6–2.2 g/kg across 3–4 meals rather than one huge dinner.

03

Recovery sleep

Hard training in a surplus still fails on five hours of sleep.

04

Honest activity tier

Underestimating NEAT means you are not actually in a surplus.

05

Rate of gain

Fast scale jumps are mostly glycogen, water and fat — not new muscle.

06

Cardio dose

Keep conditioning, but do not outrun the surplus with endless easy miles.

Method

How this calculator gets to your number

Same Mifflin-St Jeor (or Katch-McArdle) engine as the homepage — with one extra step for this use case.

Run it with my numbers
  1. 1

    Resting burn (BMR)

    Mifflin-St Jeor from age, sex, height and weight. Enter body fat and we switch to Katch-McArdle for leaner or muscular bodies.

  2. 2

    Activity multiplier

    Match the whole week — not your hardest training day. A one-tier mistake usually adds or subtracts 200–400 kcal.

  3. 3

    Surplus sizing

    A small, transparent adjustment for this page’s audience. We keep factors conservative so you can verify with a two-week weight average.

Pick a direction

Ways to run a gain phase

Choose based on how lean you want to stay.

+200–300 kcal

Lean bulk

— —kcal / day

Best default. Slow scale rise, steady lifts, minimal fat regain.

Get my number
Eat at TDEE

Recomp

— —kcal / day

Works best for novices or returning lifters. Track measurements, not only weight.

Get my number
−300 kcal, 3–6 weeks

Mini-cut

— —kcal / day

Use when surplus fat gain gets uncomfortable, then resume the lean bulk.

Get my number

Highest return first

Habits for a clean gain

Keep the surplus intentional.

  1. #1

    Log lifts weekly

    The training log is the real progress chart in a bulk.

  2. #2

    Waist check every 2 weeks

    If the waist races ahead of strength, cut the surplus.

  3. #3

    Keep steps from collapsing

    Desk days still need a NEAT floor or “surplus” calories vanish into inactivity.

  4. #4

    Plan the end date

    8–16 week gain blocks beat perpetual dirty bulks.

FAQ

Questions about TDEE muscle gain

Short, direct answers. If yours is missing, ask and we will add it.

Ask a question

Usually 200–300 kcal for intermediates. Novices can use a bit more; advanced lifters often stay near +100–200.

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