2026-09-15 9 min

Macro Calculator for Weight Gain

Lean-gain macros with a 300 kcal surplus and 25/50/25 split — target calories plus protein, carb, and fat grams that minimize fat spillover.

Calculator

Gender

Units

Age

yrs

Full years

Height

Barefoot standing height

Weight

lbs

Morning scale weight

Activity

MissionWeight gain (+300 kcal) — 25/50/25 split

Results update live as you type

Status:Maintenance 2,557 kcalTarget 2,857 kcalMaintenance — see cards

Results

Daily Target2,857 kcal

Protein178.6 g

Carbs357.1 g

Fat79.4 g

Protein per kg2.56 g/kg

TDEE plus the phase mission

Recommendations

▸Maintenance target 2,857 kcal/day at 25/50/25 (P/C/F)
▸178.6 g protein (2.56 g/kg) — above 2.4 g/kg; extra protein adds little
▸357.1 g carbs and 79.4 g fat — about 59.5 g protein per meal over 3 meals
▸Pair with 40 g fiber (14 g per 1,000 kcal) from whole grains, legumes, fruit, and vegetables
▸Confirm with 2-4 weeks of trend; re-run per 10-15 lbs of change

Results

Normal

Daily Target

2,857 kcal

TDEE plus the phase mission

Protein

178.6 g

Daily grams with g/kg in the next card

Carbs

357.1 g

Daily grams including training fuel

Fat

79.4 g

Daily grams at 9 kcal/g

Protein per kg

2.56 g/kg

Against the 1.6-2.2 active band

Mifflin-St Jeor with standard activity factors; 4/4/9 energy densities. Estimates within ~10-15% — 2-4 weeks of trend confirms or corrects.

Visualizations

Macro grams per day

178.6Protein

357.1Carbs

79.4Fat

Calorie share

Protein cal25%

Carb cal50%

Fat cal25%

Target vs adult range

2,857kcal

1,2004,000

Formula

The weight gain mission priced for your body at a 25/50/25 split.

Target = TDEE +300; grams from 25/50/25 split

Alternative Form

Protein, carbs /4; fat /9; per-meal = daily / meals

Variables

Symbol	Name	Unit	Description
BMR	Resting burn	kcal/day	Mifflin-St Jeor estimate at complete rest
TDEE	Maintenance	kcal/day	BMR scaled by activity — intake that holds weight
Target	Plan intake	kcal/day	TDEE plus the phase mission
P/C/F	Macro grams	g/day	Calorie shares divided by 4/4/9 energy densities

Explanation

The weight gain mission priced for your body: target intake plus gram goals.

Derivation

BMR via Mifflin-St Jeor. TDEE = BMR x 1.2/1.375/1.55/1.725/1.9. Split normalized to 100, then grams = target x share / density.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Price rest with Mifflin-St Jeor from your stats.

M 10W+6.25H-5A+5; F 10W+6.25H-5A-161

Resting:1,650 kcal

Intermediate: Organs billing at complete rest

Result: Resting = 1,650 kcal

Step 2

Scale rest to the full day with the activity factor.

TDEE = BMR x activity factor

Maintenance:2,557 kcal

Intermediate: Moderate x1.55

Result: Maintenance priced for your week

Step 3

Apply the phase mission to get the daily target.

Target = TDEE +/- mission amount

Target:2,857 kcal

Intermediate: Maintenance

Result: Daily intake target set

Step 4

Normalize the split so shares sum to 100.

Share = part / total x 100

Split:25/50/25

Intermediate: Protein/carb/fat shares of calories

Result: Split confirmed at 25/50/25

Step 5

Convert each calorie share into grams.

Protein, carbs /4; fat /9

Grams:178.6 / 357.1 / 79.4 g

Intermediate: Energy densities divide the shares

Result: Gram targets set for the day

Step 6

Divide protein across meals and confirm the range.

Per-meal = protein / meals; check g/kg

Rule:59.5 g/meal; 2.56 g/kg

Intermediate: 178.6 g protein (2.56 g/kg) — above 2.4 g/kg; extra protein adds little

Result: Maintenance target 2,857 kcal/day at 25/50/25 (P/C/F)

Final Answer

2,857 kcal

Worked Examples

See how the calculator works with different scenarios.

Scenario

A 30-year-old man, 175 cm, 70 kg, moderate activity.

Inputs

Stats:175 cm / 70 kg

Activity:Moderate x1.55

Calculation

BMR = 1648.8. TDEE = 1648.8 x 1.55 = 2,556. Target = 2,556 +300 = 2,856.

Result

Target ~2,856 kcal: 179 g protein, 357 g carbs, 79 g fat

Interpretation

Protein lands at 2.6 g/kg; hold 3-4 weeks of trend to confirm the rung before adjusting.

Understanding Your Result

Your Result: Daily Target: 2,857 kcal

Typical range: Protein 1.6-2.2 g/kg; AMDR 10-35 / 45-65 / 20-35; deficits 250-750/day; surpluses 150-400/day; maintenance validates by flat 2-4 week trend.

What This Means

Lean-gain macros with a 300 kcal surplus and 25/50/25 split — target calories plus protein, carb, and fat grams that minimize fat spillover.

Why It Matters

The weight gain mission priced for your body at a 25/50/25 split.

Professional Interpretation

Grow movement before cutting food and keep protein plus lifting under any mission — components decide composition, totals decide the scale.

Totals validate, splits guide

The headline total confirms by scale trend; the split chooses training quality and fullness.

Floors are real

Eating below resting burn for long costs muscle, hormones, and adherence.

Recommendations

•Confirm any number with 2-4 weeks of trend
•Protein 1.6-2.2 g/kg with lifting under every goal
•Re-run per 10-15 lbs or training-block change
•Steps before cuts; fuel before assuming surplus failed
•One mission at a time — cut, hold, or gain in phases

Educational Content

Introduction

Lean-gain macros with a 300 kcal surplus and 25/50/25 split — target calories plus protein, carb, and fat grams that minimize fat spillover.

Concept Explanation

Pin maintenance from your stats, apply the phase mission, then split the target into protein, carb, and fat grams by energy density.

Applications

▸Setting phase calories before choosing foods

▸Converting one calorie target into shoppable gram goals

▸Comparing cuts, holds, and gains on equal math

▸Fueling training blocks without guesswork

▸Re-estimating needs as body size changes

▸Explaining stalls with numbers not guilt

Benefits

•One headline intake with weekly equivalents
•Gram targets for all three macros
•Per-meal portions built in
•Reference-band checks on protein and fiber
•Trend-first validation guidance

Limitations

•Estimates within ~10-15%, not lab measures
•Single-day snapshot; training and rest days differ
•Activity rungs average diverse lives
•Water and glycogen mask fat pace for 2-3 weeks

Best Practices

•Weigh mornings before food for repeatable inputs
•Log honestly 2-4 weeks before judging
•Hit protein first, then fill carbs and fat
•Lift 2-4x weekly under every goal
•Re-run per 10-15 lbs of change

Common Misconceptions

Myth: The split matters more than the total.

Truth: Calories decide the scale; protein decides composition; the remaining split tunes training and fullness.

Myth: Exercise calories should be eaten back.

Truth: Activity is already inside TDEE here. Eating it back double-counts and erases the mission.

Myth: Faster always finishes sooner.

Truth: Oversized deficits stall via burnout and muscle loss; right-sized finishes first.

Practical Tips

•Validate every estimate with 2-4 weeks of trend
•Hold protein 1.6-2.2 g/kg with 2-4 lifts weekly
•Add steps before cutting food deeper
•Re-run per 10-15 lbs of change
•Keep one mission per phase
•Sleep 7+ hours; short sleep masks fat loss

Common Mistakes

Using goal weight instead of current weight

Equations describe the body burning now. Current weight sets today burn; re-run as you change.

Picking too-high activity

Choose the lower rung when between levels. Overestimated burn is the top cause of stalled progress.

Judging by daily scale noise

Use 7-14 day averages. Water swings kilograms; fat pace reveals over weeks.

Changing splits weekly

Hold one split 3-4 weeks. Constant redesign hides whether anything worked.

Ignoring fiber while chasing macros

Anchor 14 g fiber per 1,000 kcal first, then fit remaining carbs around it.

Assumptions

This calculator makes the following assumptions to provide estimates:

Mifflin rest: BMR from Mifflin-St Jeor with metric internals.

Standard multipliers: Activity factors 1.2 through 1.9 for the five rungs.

Energy densities: Protein and carbs 4 kcal/g; fat 9 kcal/g.

Rounded ledger: Whole-gram outputs summing near the headline total.

Limitations

Be aware of these limitations when using this calculator:

Estimated, not measured: Only the trend validates; treat splits as directions.

Rung coarseness: Five factors average diverse weeks.

No medical tailoring: Pregnancy, teens, and clinical cases need professional guidance.

Snapshot day: Training and rest days differ in reality.

Frequently Asked Questions

Answers to common questions about this calculator.

How big should the surplus be?

200–300 kcal over maintenance: ~0.25–0.5 lb/week. Bigger surpluses mostly add fat, not muscle.

Why so many carbs for gaining?

Carbs fuel progressive training and spare protein for growth. 4–6 g/kg supports hard gain phases.

Gaining too fast?

Trim 100–150 kcal (usually carbs) when the 3-week trend exceeds ~0.5 lb/week.

What are macronutrients?

Protein, carbohydrate, and fat — the nutrients you need in large amounts. Protein and carbs yield 4 kcal/g; fat yields 9 kcal/g.

How are macro grams calculated from calories?

Grams = calories × share ÷ energy density: protein and carbs ÷ 4, fat ÷ 9. A 2,000 kcal day at 30/40/30 gives 150 g protein, 200 g carbs, 67 g fat.

What is a good starting macro split?

30% protein, 40% carbs, 30% fat suits most active adults. Raise protein when dieting, raise carbs when training hard.

How much protein do active adults need?

1.6–2.2 g per kg daily with training; 1.2–1.6 g/kg for general activity; 0.8 g/kg is the RDA minimum.

When should I recalculate macros?

Per 10–15 lbs of weight change, each training-block change, or when progress stalls 3+ weeks with honest tracking.

Do I need to eat back exercise calories?

No — activity is already inside maintenance via the activity factor. Eating them back double-counts.

How accurate are these nutrition estimates?

Within about 10–15% when stats and activity are honest. Validate against 2–4 weeks of trend: stable weight confirms maintenance, steady drift corrects it.

Should I use current or goal weight?

Current weight. Equations describe the body you have. Re-run per 10–15 lbs of change as needs fall with size.

What activity level should I pick?

Price your real week: desk job with 3 lifts is light-moderate, not heavy. When between rungs, pick the lower one and let the scale confirm.

Do I need to hit macros exactly every day?

No. Weekly averages decide outcomes. Land within ~5–10 g of protein and ~10–15 g of carbs and fat most days.

Should macros differ on rest days?

Optional. Identical daily targets work well; a common refinement trims carbs on rest days while holding protein and fat.

Related Calculators

Explore more calculators related to this topic.

Related Guides

Deepen your understanding with these educational resources.

Protein and Strength While Dieting

Keep the engine while shrinking the chassis.

Setting Calories for Fat Loss

From maintenance to deficit without muscle loss.

Fueling Muscle Gain

Small surpluses plus protein and lifting.

Glossary

Technical terms used in mortgage calculations explained in plain language.

Macronutrient: Protein, carbohydrate, or fat — nutrients needed in gram amounts for energy and structure.
TDEE: Total Daily Energy Expenditure: BMR plus digestion, daily movement, and training.
BMR: Basal Metabolic Rate: calories burned at complete rest for vital functions.
AMDR: Acceptable Macronutrient Distribution Range: 10–35% protein, 45–65% carbs, 20–35% fat.
Thermic effect: Digestion cost: ~20–30% for protein, 5–10% for carbs, 0–3% for fat.
Lean mass: Body weight minus fat — muscle, bone, water, and organs; the main driver of BMR.
Energy balance: Intake minus expenditure: negative loses, positive gains, zero maintains.
Refeed: Planned higher-intake days used to relieve diet fatigue during long cuts.

Authoritative References

Trusted sources and standards referenced by this calculator.

U.S. Dietary Guidelines for Americans Harvard Nutrition Source — Macronutrients WHO — Healthy diet fact sheet NIH Office of Dietary Supplements Academy of Nutrition and Dietetics CDC — Nutrition resources

Applicable Standards

Mifflin-St Jeor (AJCN 1990)U.S. Dietary Guidelines AMDR bandsFAO/WHO/UNU human energy requirements

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Page Information

Last Updated:

2026-09-15

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.