2026-09-16 9 min

Muscle Building Calculator

Muscle-building plan from body weight, surplus and protein: targets, monthly gain and plan score.

Calculator

Body Weight kg

Daily Surplus kcal

Daily Protein g

Results update live as you type

Status:2,775 kcal/daySweet spot for lean gains.Score 90/100

Muscle Building Calculator Results

Score90

Daily Target2,775 kcal/day

Protein150 g protein

Monthly Gain1.2 kg/month

Surplus300 kcal surplus

VerdictSweet spot for lean gains.

Target 2,775 kcal (2,475 maintenance + 300), protein 150 g (2 g/kg) — about 1.2 kg/month. Sweet spot for lean gains. On target for growth.

Building Plan Breakdown

Measure	Value	Context
Daily target	2,775 kcal	2,475 + 300
Maintenance	2,475 kcal	33 kcal x 75 kg
Surplus	300 kcal	Sweet spot for lean gains.
Protein	150 g	2 g/kg — On target for growth.
Monthly gain	1.2 kg	surplus x 30 / 7700
Verdict	Sweet spot for lean gains.	plan band

Recommendations

▸Hold the plan 4 weeks minimum — tissue change is slower than water noise.
▸Target 2,775 kcal (2,475 maintenance + 300), protein 150 g (2 g/kg) — about 1.2 kg/month. Sweet spot for lean gains. On target for growth.

Results

Optimal

Plan Score

90/100

Bulk plan rating

Daily Target

2,775 kcal/day

Maintenance + surplus

Protein

150 g protein

Daily grams

Monthly Gain

1.2 kg/month

Projected tissue

Surplus

300 kcal surplus

Above maintenance

Verdict

Sweet spot for lean gains.

Plan band

Gain math is exact arithmetic on your inputs; rate bands reflect published beginner-to-advanced monthly averages, not personal guarantees.

Visualizations

Daily gauges

277.5Target /10

150Protein

116.9Gain x100

Surplus vs 600 kcal cap

Your surplus50%

To cap50%

Gain Plan Score

Score90/100

Formula

A weight-based maintenance estimate plus a capped surplus sets the bulk; protein per kilo validates it.

Target = 33 x weight + surplus; monthly gain = surplus x 30 / 7700

Alternative Form

Protein target = 1.6-2.2 g per kg of body weight

Variables

Symbol	Name	Unit	Description
W	Body weight	kg	Morning fasted weight
M	Maintenance	kcal	33 x W estimate
S	Surplus	kcal	Calories above maintenance
P	Protein	g/kg	Daily protein per kilo
G	Monthly gain	kg	S x 30 / 7700

Explanation

Tissue costs ~7,700 kcal per kilo, so a 300 kcal surplus predicts ~1.2 kg monthly scale gain, part muscle and part support tissue.

Derivation

Energy-balance arithmetic with ISSN protein guidance and coaching surplus bands.

Step-by-Step Calculation

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

Step 1

Estimate maintenance from body weight.

Maintenance = 33 x kg

Weight:75 kg

Intermediate: 33 x 75

Result: 2,475 kcal maintenance

Step 2

Add the gaining surplus.

Target = maintenance + surplus

Maintenance:2,475 kcal

Surplus:300 kcal

Intermediate: 2475 + 300

Result: 2,775 kcal daily target

Step 3

Check protein per kilo.

g/kg = protein / weight

Protein:150 g

Weight:75 kg

Intermediate: 150 / 75

Result: 2.0 g/kg — on target

Step 4

Project monthly tissue.

kg/month = surplus x 30 / 7700

Surplus:300 kcal

Intermediate: 300 x 30 / 7700

Result: ~1.2 kg/month scale gain

Step 5

Band the surplus.

Sweet spot = 150-500 kcal

Surplus:300 kcal

Intermediate: band lookup

Result: Sweet spot for lean gains

Step 6

Score the plan.

Surplus band + protein band

Bands:both on target

Intermediate: 45 + 40 + 5

Result: Plan score = 90/100

Final Answer

90/100

Worked Examples

See how the calculator works with different scenarios.

Scenario

75 kg, 300 kcal surplus, 150 g protein.

Inputs

Weight:75 kg

Surplus:300 kcal

Protein:150 g

Calculation

Target 2,775 kcal; protein 2.0 g/kg

Result

~1.2 kg/month, score 90

Interpretation

Textbook lean bulk. Hold 4-6 months.

Understanding Your Result

Your Result: Plan Score: 90/100

Typical range: Lean gain runs 0.1-0.25 kg weekly; surpluses of 250-350 kcal and protein of 1.6-2.2 g/kg support it.

What This Means

The output turns body weight and goals into a weekly gain rate, daily surplus and protein target with a 0-100 plan score.

Why It Matters

Most bulks fail by overshooting the surplus (gaining fat) or undershooting protein and progression (gaining nothing). Numbers prevent both.

Professional Interpretation

Coaches cap beginner bulks near 1% of body weight monthly and halve that each training year, adjusting from waist and lift trends.

Surplus math

One kilogram of tissue costs roughly 7,700 kcal, so 0.25 kg weekly needs about a 275 kcal daily surplus.

Scale vs mirror

Daily weigh-ins averaged weekly beat single readings; waist trends separate muscle from fat gains.

Recommendations

•Hold a 250-350 kcal surplus
•Eat 1.6-2.2 g/kg protein daily
•Progress lifts every 1-2 weeks
•Cap bulks at 4-6 months before a cut

Educational Content

Introduction

This calculator plans lean muscle gain: rate, calories, protein and timeline in one place.

Concept Explanation

Small sustained surpluses plus progressive training partition calories toward muscle; oversized surpluses partition toward fat.

Applications

▸Lean bulk planning

▸Goal timelines

▸Surplus calibration

▸Protein targeting

▸Bulk-vs-cut decisions

▸Plateau audits

Benefits

•Realistic rate bands
•Exact surplus math
•Protein targets
•Timeline honesty
•0-100 plan score

Limitations

•Individual variance
•Water-weight noise
•Beginner vs advanced spread
•No body-fat modeling
•Static maintenance estimate

Best Practices

•Weigh daily, average weekly
•Track waist with weight
•Hold protein steady first
•Adjust surplus in 100 kcal steps
•Bulk 4-6 months, then reassess

Common Misconceptions

Myth: Eat big to get big fast.

Truth: Surpluses above ~500 kcal add mostly fat. Muscle synthesis caps out; extra calories cannot force extra growth.

Myth: More protein always helps.

Truth: Benefits plateau near 2.2 g/kg. Beyond that, carbs that fuel training beat extra protein.

Myth: Scale weight equals muscle.

Truth: Glycogen, water and gut content swing kilograms. Only multi-week trends plus strength count.

Practical Tips

•Average 7 daily weigh-ins weekly
•Photograph monthly in equal light
•Keep protein within 10 g of target daily
•Add 100 kcal when weight stalls 2 weeks
•Sleep 7-9 hours for growth hormone release
•Deload every 4-8 weeks to keep gaining

Common Mistakes

Dirty bulking

A 1,000 kcal surplus builds fat, not faster muscle. Cap at 250-350 kcal and accept slower scale moves.

Protein guessing

Most lifters overestimate intake by 30-50 g. Track for two weeks to calibrate, then eat on autopilot.

Program hopping

Switching plans monthly resets adaptation. Run one program 8-12 weeks before judging it.

Ignoring the waist

A climbing waist with stalled lifts means fat gain. Hold or trim the surplus immediately.

Cutting every bulk short

Three-week bulks build nothing. Commit 4-6 months, then cut decisively.

Training without progression

Same weights mean same muscles. Beat last week by a rep or 2.5% regularly.

Assumptions

This calculator makes the following assumptions to provide estimates:

Healthy adult: Math fits healthy adults; teens, seniors and medical cases differ.

Consistent training: Assumes 3-5 progressive sessions weekly alongside the nutrition.

Stable maintenance: Maintenance is estimated from body weight; metabolic adaptation is not modeled.

Honest inputs: Body weight is a morning fasted average, not a post-meal reading.

Drug-free rates: Rate bands reflect natural lifters; enhanced rates differ wildly.

Limitations

Be aware of these limitations when using this calculator:

Maintenance estimate: True maintenance varies 10-15% around the estimate; adjust from scale trends.

No body-fat input: Partitioning quality depends on leanness, which this math cannot see.

Water noise: Creatine, carbs and sodium swing kilograms that mimic or hide tissue change.

Experience spread: Beginner-to-advanced is a spectrum; self-grading shifts the bands.

Static projection: Linear timelines ignore adaptation slowdown; re-run monthly.

Frequently Asked Questions

Answers to common questions about this calculator.

How fast can I gain muscle?

Beginners gain roughly 0.5-1 kg per month, intermediates 0.25-0.5 kg, advanced lifters under 0.25 kg. Faster scale gains are mostly fat and water.

How big a calorie surplus?

About 250-350 kcal daily (roughly 5-10% above maintenance) maximizes lean gain while limiting fat. Larger surpluses add fat, not extra muscle.

How much protein to build muscle?

1.6-2.2 g per kg of body weight daily, spread over 3-5 meals with 0.3-0.5 g/kg each. More than 2.2 g/kg shows no further muscle benefit.

Should I bulk or cut first?

Above ~20% body fat (men) or ~30% (women), cut first — extra fat worsens nutrient partitioning. Leaner lifters gain better on a small surplus.

How long to gain 5 kg of muscle?

A dedicated beginner needs roughly 8-12 months; an intermediate 18-24 months. Muscle accrues in months and years, not weeks.

Do I need progressive overload to grow?

Yes. Muscle adapts to rising tension, so lifts must climb over time via weight, reps or sets. Same weights mean same muscles.

Can I build muscle and lose fat together?

Beginners, detrained and high-body-fat lifters can recomp at maintenance calories. Lean intermediates need distinct bulk and cut phases.

How do I know gains are muscle, not fat?

Track strength on key lifts, waist circumference and scale weight together. Rising lifts with a stable waist mean lean gains.

What stalls muscle gain most often?

Too-small surplus, protein under 1.6 g/kg, under-sleeping, program-hopping, and never deloading. Fix food and sleep before changing programs.

How much sleep for muscle growth?

Seven to nine hours. One week of short sleep measurably blunts muscle protein synthesis and spikes hunger hormones.

Do I need supplements to grow?

No. Creatine monohydrate (3-5 g daily) is the only supplement with strong muscle evidence; everything else is optional once food and training are right.

When should I stop bulking?

Cap bulks at ~20% body fat for men or ~30% for women, or after 4-6 months, then cut 8-12 weeks to restore insulin sensitivity and appetite control.

Related Calculators

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Related Guides

Deepen your understanding with these educational resources.

Getting Started with Strength Training

Progressive overload, volume landmarks and recovery basics.

Cardio Training Essentials

Zones, VO2 max and weekly aerobic volume that actually moves fitness.

Nutrition for Active People

Protein, calories and hydration to support training and recovery.

Understanding Recovery

Sleep, rest days and deloads that turn training into adaptation.

Glossary

Technical terms used in mortgage calculations explained in plain language.

Lean mass: Body weight minus fat mass: muscle, bone, water and organs.
Surplus: Calories eaten above maintenance; the fuel for new tissue plus some fat.
Progressive overload: Gradually raising training stress so muscle keeps adapting.
Beginner gains: Rapid early progress from neural adaptation plus novel stimulus.
Nutrient partitioning: Where surplus calories go — muscle vs fat — driven by training, leanness and protein.
Recomp: Simultaneous fat loss and muscle gain, viable mainly for beginners.
Meso cycle: A 4-8 week training block ending in a deload.
Deload: Planned easy week that consolidates gains and sheds fatigue.
FFMI: Fat-free mass index; ~25 is near the natural ceiling for most men.
Protein synthesis: The repair process that builds muscle after training; elevated ~24-48 hours.
Maintenance calories: Intake holding body weight stable; bulks add 5-10% above it.
Mini-cut: A short 4-6 week fat-loss phase inside a long gaining period.

Authoritative References

Trusted sources and standards referenced by this calculator.

ACSM — Exercise guidance and resources ISSN — Sports nutrition position stands CDC — Physical activity guidelines WHO — Physical activity fact sheets NIH — Exercise and health information NSCA — Strength and conditioning resources AtlasCalcs — Health resources

Applicable Standards

ISSN position stand on protein and exercise (1.4-2.0 g/kg/day)ACSM Guidelines for Exercise Testing and PrescriptionWHO/FAO energy requirement guidelines

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Page Information

Last Updated:

2026-09-16

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.