2026-08-07 8 min

Target Body Fat Calculator

Find the exact scale weight that puts your current lean mass at any target body fat percent, with weight change, target fat kilograms, and category.

Calculator

Gender

Units

Current Weight

Morning scale weight

Current Body Fat

Measured or estimated percent

Target Body Fat

Any percent above 0

Age

yrs

For ideal comparison

Results update live as you type

Status:Target Weight 76.7 kgWeight Change -8.3 kg

Target Weight Results

Target Weight76.7 kg

Weight Change-8.3 kg

Current Lean62.9 kg

Target Fat Mass13.8 kg

Target CategoryAverage

Target Breakdown

Measure	Value
Target Weight	76.7 kg
Weight Change	-8.3 kg
Current Lean	62.9 kg
Target Fat Mass	13.8 kg
Target Category	Average
Age Ideal	13.1%

Recommendations

▸Cut 8.3 kg at 0.5-1% weekly with protein and lifting to land 76.7 kg

Results

Optimal

Target Weight

76.7 kg

Weight carrying current lean at target percent

Weight Change

-8.3 kg

Negative for cuts, positive for gains

Current Lean

62.9 kg

Held fixed by the model

Target Fat Mass

13.8 kg

Fat kilograms at the target

Target Category

Average

ACE band at the target percent

Age Ideal

13.1%

Jackson and Pollock reference

Targets assume preserved lean mass. Gaining muscle raises every target weight; losing it lowers them. Recompute after training blocks.

Visualizations

Now vs Target

85Now

76.7Target

Target Composition

Target fat18%

Lean held82%

Target Level

Target fat18%

Formula

Current lean mass anchors the math: it is weighed today, then re-expressed at the target fraction to reveal the matching scale weight.

Target weight = lean mass / (1 - target%)

Alternative Form

Weight change = target weight - current weight

Variables

Symbol	Name	Unit	Description
TW	Target weight	kg/lbs	Scale weight at the target percent
LM	Lean mass	kg/lbs	Current lean compartment, held fixed
CHG	Weight change	kg/lbs	Negative for cuts, positive for gains
TF	Target fat mass	kg/lbs	Fat kilograms at the target

Explanation

Percent and weight are two views of one body. Fixing lean mass links them, so each target percent maps to exactly one scale weight.

Derivation

Lean = W x (1 - BF%). Target = Lean/(1 - T%). Change = Target - W. Target fat = Target x T%.

Step-by-Step Calculation

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

Step 1

Weigh lean mass from current weight and percent.

Lean = weight x (1 - BF%)

Weight:85

Body fat:26%

Intermediate: The fixed anchor for every target

Result: Lean = 62.9 kg

Step 2

Re-express that lean at the target fraction.

Target = lean / (1 - target%)

Target:18%

Intermediate: One percent, one matching weight

Result: Target = 76.7 kg

Step 3

Subtract for the required change.

Change = target - current

Change:-8.3 kg

Intermediate: Negative means cut, positive means gain

Result: Change = -8.3 kg

Step 4

Price the target in fat kilograms.

Target fat = target x target%

Target fat:13.8 kg

Intermediate: What the fat compartment becomes

Result: 13.8 kg of fat at goal

Step 5

Band the target with ACE categories.

Band = ACE(target%, gender)

Band:Average

Intermediate: Athlete, fitness, average, or obese

Result: Target sits in Average

Step 6

Compare against the age-adjusted ideal.

Ideal = Jackson-Pollock(age)

Ideal:13.1%

Intermediate: A population anchor, not a mandate

Result: Cut 8.3 kg at 0.5-1% weekly with protein and lifting to land 76.7 kg

Final Answer

76.7 kg

Worked Examples

See how the calculator works with different scenarios.

Scenario

An 85 kg male at 26% targeting 18%.

Inputs

Weight:85 kg

Current:26%

Target:18%

Calculation

Lean = 85 x 0.74 = 62.9 kg. Target = 62.9 / 0.82 = 76.7 kg. Change = -8.3 kg. Target fat = 76.7 x 0.18 = 13.8 kg.

Result

Target weight 76.7 kg, change -8.3 kg (Fitness)

Interpretation

An 8-kilo cut at half a kilo weekly is a 4-month project. Strength work keeps the 62.9 kg of lean.

Understanding Your Result

Your Result: Target Weight: 76.7 kg

Typical range: Popular first targets: 20% then 15% for men; 28% then 24% for women. Adjust for sport and build.

What This Means

The target weight is the exact scale reading where your current lean mass meets the chosen body fat percent.

Why It Matters

Goals like get leaner stall without a number. This converts any percent into the scale weight to chase.

Professional Interpretation

Pick targets in 3-5 point steps. Each step is one training block with its own calories and review date.

Recommendations

•Step targets 3-5 points at a time
•Cut toward lower targets at 0.5-1% weekly
•Gain toward higher targets slowly with lifting
•Recompute lean mass every training block
•Judge the band, not just the digits

Educational Content

Introduction

This calculator answers the most practical composition question: what must I weigh to be a given percent with the muscle I have?

Concept Explanation

Lean mass is conserved in the model, so body fat percent and scale weight become two expressions of one unknown — solved directly.

Applications

▸Turning I want 15% into a scale number

▸Staging multi-phase cuts with intermediate targets

▸Sanity-checking coach or app goal weights

▸Planning lean gains without excess fat

▸Comparing targets across methods consistently

Benefits

•Exact weight for any percent instantly
•Handles cuts and gains in one equation
•Bands every target with ACE context
•Anchors to an age-adjusted ideal
•Live what-if across the whole percent range

Limitations

•Lean mass is assumed fixed between weigh-ins
•Water and glycogen ignored
•Bands are population norms
•Not a medical prescription

Best Practices

•Measure lean from a trusted percent
•Target 3-5 points at a time
•Review every 4-6 weeks
•Train for the body you are keeping
•Sleep and protein before harder deficits

Common Misconceptions

Myth: Any target weight works if I diet hard enough.

Truth: Below-essential targets break health before they break plateaus. Respect the floor.

Myth: Gaining weight always means getting fatter.

Truth: At a higher target percent with more muscle, a heavier weight can be leaner in the ways that matter.

Myth: One target lasts forever.

Truth: Muscle changes move every target. Recompute after each block.

Practical Tips

•Measure first thing in the morning before food for repeatable numbers
•Use the same tape, scale, and landmarks every time
•Average three tape pulls per site instead of trusting one
•Track the 4-week trend, not day-to-day noise
•Pair the scale with waist and progress photos
•Re-run the numbers after every 3-5 kg of weight change

Common Mistakes

Comparing different methods as if they match

Pick one method and track it. Navy, skinfold, and DEXA can differ by 3-5 points on the same body.

Measuring after meals or training

Food, water, and pump change weight and circumferences. Measure fasted and rested.

Pulling the tape too tight or too loose

Snug without compressing skin, level, at end-exhale. Practice the same tension each time.

Chasing daily fluctuations

Weigh 3-4 times per week and compare weekly averages; fat loss is a trend.

Cutting calories so hard that muscle is lost

Keep protein near 1.6-2.2 g per kg and lift 2-4 times weekly while in a modest deficit.

Assumptions

This calculator makes the following assumptions to provide estimates:

Fat-only change model: Goal math assumes fat is lost while lean mass is preserved through protein and training.

Stable hydration: Readings assume normal hydration; dehydration and glycogen swings shift weight and tapes.

Consistent technique: Tape landmarks, tension, and timing match between measurements.

Adult norms: ACE bands and ideals apply to adults 18 and over, not children or athletes under supervision.

Energy math: One kilogram of body fat is treated as about 7,700 kcal for timeline estimates.

Limitations

Be aware of these limitations when using this calculator:

Estimate, not a scan: Field equations carry 3-4 points of error versus DEXA; treat results as a working estimate.

Single-day variability: Food, sodium, sleep, and training move weight and waist day to day.

No medical diagnosis: This tool screens composition; it does not diagnose obesity or metabolic disease.

Muscle confounds weight math: Very muscular builds read heavier at the same leanness; photos and strength track progress too.

Frequently Asked Questions

Answers to common questions about this calculator.

What weight will I be at 15% body fat?

Divide your lean mass by 0.85. Enter your numbers above and the calculator solves it for any percent you pick.

Does the target assume I keep muscle?

Yes. Lean mass is held fixed, so cuts target fat only. Lift and eat protein to make the assumption true.

Can the target be above my current weight?

Yes, when the target percent is near or above current — that is a recomp or lean-gain path, and the change shows positive.

How is this different from BMI goal weight?

BMI targets weight-for-height; this targets composition. Two lifters with one BMI can have different target weights here.

Which target percent should I pick?

Anchor on the age-adjusted ideal, then adjust for sport and preference. Fitness bands suit most active adults.

Why does age change the ideal?

Healthy body fat drifts up with age in population data. The Jackson and Pollock table reflects that pattern.

What if I gain muscle during the cut?

Then every target weight rises. Recompute lean mass after each training block and enjoy the higher target.

How fast should I move to target?

Cut at 0.5-1% of body weight weekly. Gain at roughly half that to keep gains lean.

Do men and women use the same math?

Identical equations; only the category bands and ideals differ by gender.

Can I target below essential fat?

The math runs, but physiology objects. Stay above 5% (men) or 10-13% (women) for health.

How often should I recompute?

Every 3-5 kg or after each training block, since lean mass is the moving anchor.

Is this a medical prescription?

No. It is planning arithmetic. Extreme targets deserve a clinician or registered dietitian.

Related Calculators

Explore more calculators related to this topic.

Related Guides

Deepen your understanding with these educational resources.

Body Composition Basics

Fat mass, lean mass, and what healthy ranges look like.

How to Cut Without Losing Muscle

Protein, lifting, and deficit sizing for fat loss.

Tape-Measure Best Practices

Landmarks, tension, and timing for repeatable readings.

Glossary

Technical terms used in mortgage calculations explained in plain language.

Body fat percentage: Share of total body weight made up of fat tissue, expressed as a percent.
Fat mass: Kilograms or pounds of body weight that are fat tissue.
Lean mass: Body weight minus fat mass: muscle, bone, water, and organs.
Essential fat: Minimum fat needed for normal physiology; about 2-5% for men and 10-13% for women.
ACE categories: Athlete, fitness, average, and obese bands published by the American Council on Exercise.
Siri equation: Body fat percent from body density: (495 / density) - 450.
Body density: Body mass divided by body volume; estimated from skinfolds or circumferences.
Calorie deficit: Eating fewer calories than burned, forcing the body to use stored fat.
Recomposition: Losing fat while preserving or gaining lean mass through training and protein.
Plateau: A stall in fat loss, usually from adaptation, tracking drift, or water retention.

Authoritative References

Trusted sources and standards referenced by this calculator.

American Council on Exercise — Body Fat Percentage CDC — Healthy Weight Assessment Jackson & Pollock — Generalized equations for predicting body density Hodgdon & Beckett — Prediction of percent body fat (Navy method) Deurenberg et al. — Body mass index as a measure of body fatness NIH — Clinical Guidelines on Overweight and Obesity WHO — Obesity and overweight fact sheet

Applicable Standards

ACE body fat percentage normsJackson & Pollock age-adjusted idealsWHO healthy weight guidance

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Page Information

Last Updated:

2026-08-07

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.