Goal Weight Calculator

Goal Weight Calculator: Set a Realistic Target Weight Using Height, Frame, and Body Composition

TL;DR: There is no single correct goal weight for a given height. The four main ideal body weight formulas (Devine, Robinson, Miller, Hamwi) produce results that differ by up to 7 kg for the same person. A healthy BMI range (18.5–24.9) spans a further 15–20 kg at most heights. The most useful goal weight is not the formula output but the weight at which your health markers, body composition, and sustainable daily habits converge. This calculator combines formula outputs with your BMI range and body fat context to give you a goal weight window rather than a single arbitrary number.

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Table of Contents

• Why "Ideal Weight" Formulas Were Never Designed for You
• Seven Reasons Your Goal Weight Needs More Than a Formula
• The Formulas, the Ranges, and How to Read Them Together
• How to Set Your Goal Weight in Six Steps
• Two Goal Weight Calculations, Fully Worked
• Six Goal Weight Mistakes That Lead to the Wrong Target
• FAQ
• Assumptions and Notes
• The Weight You Are Aiming For
• Further Reading

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Why "Ideal Weight" Formulas Were Never Designed for You

The four formulas most commonly used to estimate ideal body weight were all developed between 1964 and 1983. Not one of them was designed for general fitness or aesthetic goals. The Hamwi formula (1964) was created to estimate drug dosage thresholds in clinical settings. The Devine formula (1974) followed the same purpose and became widely used in pharmacokinetics because certain medications are dosed by lean body mass rather than total weight. Robinson and Miller both modified Devine in 1983, again for clinical rather than lifestyle applications.

None of these researchers asked: "What weight will make this person feel their best?" They asked: "What weight produces reliable pharmacological dosing?" The formulas factor in height and sex. Nothing else. No muscle mass, no bone density, no age beyond adolescence, no activity level, no fat distribution.

This matters because applying a drug-dosage formula to a personal fitness goal produces a number that may be meaningful, irrelevant, or actively misleading depending on the person. A 180 cm male powerlifter at 95 kg with 12% body fat has a Devine IBW of approximately 79 kg. Reaching 79 kg would require him to lose 16 kg of largely lean tissue. The formula is not wrong for its intended purpose; it is simply the wrong tool for setting a personal goal weight.

The calculator above combines formula outputs with BMI-range and body composition context. Run your numbers to see where all three converge.

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Seven Reasons Your Goal Weight Needs More Than a Formula

• You have a muscular build from years of resistance training. All four IBW formulas use height and sex only. A 170 cm woman who has been lifting weights for 5 years may carry 58 kg of lean body mass alone, placing her true healthy weight well above the Devine formula output of approximately 61 kg total. For anyone with above-average muscle mass, the formula IBW represents a physically impossible target without significant lean mass loss; the BMI upper boundary (24.9) is a more relevant ceiling.

• You have a small or large body frame. Bone density and skeletal frame size account for 3–5 kg of weight variation at the same height. A large-framed woman at 168 cm may have a skeletal weight 3–4 kg heavier than a small-framed woman of the same height, meaning the lower end of the IBW range is structurally unreachable without being underweight in terms of lean mass. Wrist circumference relative to height is the standard proxy for frame size; large-framed individuals should target the upper 30–40% of their IBW range.

• You are over 60 and aware that very low weight increases fracture and mortality risk. Research consistently shows that older adults (65+) have lower all-cause mortality at BMI 23–27 than at BMI 20–22, which is the lower end of the standard "healthy" range. Being slightly above the textbook ideal weight is protective in older adults due to increased muscle reserve, bone mass, and physiological resilience. A goal weight that looks overweight by a 1983 formula may be exactly right for a 68-year-old.

• Your previous lowest adult weight was achieved through restriction and was unsustainable. A goal weight is only meaningful if it can be maintained. If your lowest previous weight required chronic hunger, eliminated social eating, or coincided with hormonal disruption or fatigue, that weight is not your goal weight regardless of what any formula says. The sustainable weight is the one achievable with a lifestyle you can actually maintain, and for most people this is 3–7 kg above their historical minimum.

• You want to set a goal weight for an athletic event with weight categories. Combat sports, rowing, weightlifting, and horse racing use weight categories where the goal weight is competitive rather than health-based. In this context, the target is a specific number (the category limit) and the question is not "is this healthy?" but "can I reach this safely and perform at this weight?" Goal weights for weight-class athletes should be set at no more than 5% below their natural walking-around weight to protect performance and health.

• You are recovering from an eating disorder and need an evidence-based range rather than a single number. Clinical eating disorder recovery programmes consistently avoid giving a single target weight; instead, they define a maintenance weight range of approximately 5 kg within which the body's hunger and satiety signals normalise. A goal weight range rather than a precise target is the most appropriate framing for anyone with a history of disordered eating.

• You want to compare the formula output to where your health markers actually normalise. For many people, blood pressure, fasting glucose, and lipid markers return to healthy ranges at a weight 5–10% below their current weight, which may be well above the IBW formula output. Reaching the point where health markers are normal is more clinically meaningful than reaching any formula number. If your markers are already normal, the clinical rationale for further loss is reduced regardless of what the formulas say.

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The Formulas, the Ranges, and How to Read Them Together

Your goal weight sits inside a range defined by three overlapping frameworks: the four IBW formulas, the healthy BMI range, and an evidence-based body fat percentage target. Reading all three together produces a window rather than a point.

IBW Formula Reference (height in cm, weight in kg)

Devine (1974):
  Male:   50.0 + 2.3 × (height_in − 60)    [height in inches]
  Female: 45.5 + 2.3 × (height_in − 60)

Robinson (1983):
  Male:   52.0 + 1.9 × (height_in − 60)
  Female: 49.0 + 1.7 × (height_in − 60)

Miller (1983):
  Male:   56.2 + 1.41 × (height_in − 60)
  Female: 53.1 + 1.36 × (height_in − 60)

Hamwi (1964):
  Male:   48.0 + 2.7 × (height_in − 60)
  Female: 45.5 + 2.2 × (height_in − 60)

Healthy BMI range (18.5–24.9):
  Weight (kg) = BMI × height(m)²
  Lower bound: 18.5 × height(m)²
  Upper bound: 24.9 × height(m)²

IBW Formula Comparison at Common Heights (Male)

IBW Formula Comparison at Common Heights (Female)

Body Fat Percentage Reference Ranges by Goal

Genetic factors meaningfully affect where within these ranges an individual naturally settles. Variants in the FTO gene (carried by approximately 43% of people of European ancestry) are associated with 1.5–3 kg higher weight at a given height compared to non-carriers eating the same diet. Variants in the MC4R gene affect appetite set-point, making some individuals genuinely comfortable at weights toward the upper end of the healthy BMI range. Neither variant makes a person unhealthy within the normal range; they indicate that the specific formula IBW is likely to be an unrealistic personal target.

The key limitation of all these frameworks is that they measure weight, not health. Two people at identical weights and heights can have dramatically different body fat percentages, muscle mass, cardiovascular fitness, and metabolic health. A goal weight should be understood as the entry point to a more complete picture of health, not the destination itself.

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How to Set Your Goal Weight in Six Steps

1. Run the four IBW formulas for your height and sex. Note the spread between the lowest and highest formula output. If the spread is less than 5 kg, the formulas are in reasonable agreement. If it exceeds 7 kg, the range is wide enough that the formula outputs alone are not specific guidance.

2. Calculate your healthy BMI weight range. Multiply your height in metres squared by 18.5 (lower bound) and 24.9 (upper bound). This gives the full healthy weight window for your height. Your goal weight should fall within this range unless a medical professional has recommended otherwise.

3. Assess your frame size using wrist circumference. Measure your wrist at the smallest point. A large-framed person should target the upper 30–40% of their healthy BMI range; a small-framed person may be naturally comfortable at the lower 30–40%. This adjustment personalises the range without a formula.

4. Identify where the formula IBW sits within your BMI range. If all four formula outputs fall within your healthy BMI range, pick the midpoint of the formula cluster as a starting reference. If formula outputs fall below the lower bound of your healthy BMI range (common in tall or muscular individuals), discard them and use the lower quarter of your BMI range instead.

5. Set a goal weight range of 3–5 kg, not a single number. A specific single-kilogram target creates artificial pass/fail psychology. A 3–5 kg window (for example, 72–76 kg) allows for normal weight fluctuation, hormonal cycles, and body recomposition shifts while still defining meaningful progress. Maintenance is always a range, never a point.

6. Verify the target is achievable at a safe rate. Divide the weight to lose by 0.5 kg per week (the conservative safe rate). If the result is more than 52 weeks, consider whether the goal weight is genuinely necessary for health or whether an intermediate milestone weight would deliver comparable health benefits sooner.

Non-obvious insight: The body defends a set-point range of approximately 5–7 kg through hunger and energy expenditure adjustments. Trying to maintain a weight at the lower edge of your natural set-point requires ongoing, deliberate dietary management; maintaining a weight within the set-point range requires substantially less conscious effort. For long-term sustainability, a goal weight 3–5 kg above the absolute formula minimum is almost always more achievable than hitting and holding the exact IBW output.

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Two Goal Weight Calculations, Fully Worked

Example 1: Woman Returning to a Healthy Weight After Gradual Gain, Age 44

Fatima is 163 cm, lightly built (wrist circumference 14.5 cm, small frame for her height), weighs 78 kg, and wants to set a realistic goal weight before starting a calorie deficit plan. She has no significant athletic history.

IBW formulas (163 cm = 64.2 inches):
  Devine:   45.5 + 2.3 × (64.2 − 60) = 45.5 + 9.7 = 55.2 kg
  Robinson: 49.0 + 1.7 × (64.2 − 60) = 49.0 + 7.1 = 56.1 kg
  Miller:   53.1 + 1.36 × (64.2 − 60) = 53.1 + 5.7 = 58.8 kg
  Hamwi:    45.5 + 2.2 × (64.2 − 60) = 45.5 + 9.2 = 54.7 kg
  Formula range: 54.7–58.8 kg (spread: 4.1 kg)

Healthy BMI range at 163 cm (1.63 m):
  Lower: 18.5 × 1.63² = 18.5 × 2.657 = 49.2 kg
  Upper: 24.9 × 1.63² = 24.9 × 2.657 = 66.2 kg

Formula cluster midpoint: 56.7 kg
  All formula outputs within BMI range — relevant.

Frame adjustment: small frame → lower 35% of range
  Lower 35% of 49.2–66.2 kg = 49.2 + (0.35 × 17.0) = 55.2 kg

Goal weight range: 55–60 kg

Fatima's actionable note: her goal weight range of 55–60 kg is achievable but represents a 46-week commitment at a conservative rate. An intermediate milestone of 68 kg (the midpoint of her BMI range) delivers the 5% clinical benefit threshold at just 10 kg of loss, approximately 20 weeks in. Starting with the intermediate milestone reduces the psychological distance of the goal and delivers measurable health benefits before the final target is reached.

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Example 2: Male Recreational Weightlifter Setting a Competition Goal, Age 31

Tomasz is 178 cm, has been lifting for 6 years, weighs 88 kg, and is preparing for a local physique competition. He wants to set a lean stage weight that is realistic rather than aspirational. His current estimated body fat is 18%.

IBW formulas (178 cm = 70.1 inches):
  Devine:   50.0 + 2.3 × (70.1 − 60) = 50.0 + 23.2 = 73.2 kg
  Robinson: 52.0 + 1.9 × (70.1 − 60) = 52.0 + 19.2 = 71.2 kg
  Miller:   56.2 + 1.41 × (70.1 − 60) = 56.2 + 14.2 = 70.4 kg
  Hamwi:    48.0 + 2.7 × (70.1 − 60) = 48.0 + 27.3 = 75.3 kg
  Formula range: 70.4–75.3 kg (spread: 4.9 kg)

Lean body mass estimate:
  Fat mass: 88 × 0.18 = 15.8 kg
  Lean mass: 88 − 15.8 = 72.2 kg

Stage lean target (6% body fat for physique competition):
  Goal weight = lean mass / (1 − target body fat%)
             = 72.2 / (1 − 0.06) = 72.2 / 0.94 = 76.8 kg

Formula note: IBW formulas (70.4–75.3 kg) require Tomasz to
lose lean mass to reach them. His actual stage weight at 6%
body fat is 76.8 kg — above the formula range.

Tomasz's calculation illustrates exactly why IBW formulas fail muscular individuals: every formula output requires him to lose more weight than his total fat mass allows without lean mass reduction. His realistic stage weight is 76.8 kg — 1.5–6.4 kg above the formula range, with approximately 11 weeks of dieting at 1 kg per week to get there. His goal weight is body-composition-derived, not formula-derived, which is the correct approach for anyone with significant training history.

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Six Goal Weight Mistakes That Lead to the Wrong Target

Using a single formula output as a precise personal target. The four IBW formulas produce results up to 7 kg apart for the same person at the same height. Using only the Devine formula (the most common default) and ignoring the 4–7 kg spread gives a false impression of precision. The formula outputs are a cluster, not a point; a goal weight range covering the cluster midpoint and the lower quarter of the healthy BMI range is always more useful than any single formula number.

Setting a goal weight below the healthy BMI lower bound. A BMI below 18.5 is associated with increased all-cause mortality, increased fracture risk, immune suppression, and hormonal disruption. Some IBW formula outputs fall below the healthy BMI lower bound for shorter women, particularly the Hamwi formula for women under 160 cm. Any goal weight below the BMI 18.5 floor for your height should be reviewed with a physician before pursuing it.

Targeting the weight at which you looked best in a photograph from a decade ago. Photo weight and health weight are not the same thing. A person in a photograph 10 years younger may have been at a weight achieved through a phase of illness, extreme restriction, or a lifestyle no longer compatible with their current responsibilities. The right goal weight is the weight achievable and maintainable with the life you have now, not the body of a past self operating under different conditions.

Not adjusting for age over 60. IBW formulas have no age correction, and the healthy BMI range for older adults extends upward from the standard population range. Adults over 65 have consistently lower mortality at BMI 23–27 than at BMI 20–22. A 70-year-old setting a goal weight at the formula IBW of 63 kg when their healthy older-adult range is 68–75 kg is targeting a weight that is statistically associated with higher mortality for their age group, not lower.

Confusing goal weight with healthy weight. A goal weight is a personal planning target. A healthy weight is a range within which metabolic markers, joint health, and cardiovascular risk are optimised. These overlap but are not identical. Someone who reaches their goal weight but still has elevated blood pressure, HbA1c outside the normal range, or significant visceral fat has not reached a healthy weight in the clinically meaningful sense. Body composition change matters as much as scale number.

Setting a goal weight without an intermediate milestone. For anyone with more than 15 kg to lose, a single distant goal weight is psychologically and practically difficult to sustain. Setting an intermediate milestone at 5% below current weight (the first clinical benefit threshold) makes the plan more manageable and provides an early measurable reward. Achieving the 5% milestone and holding it for 4–8 weeks before targeting the next 5% is a more reliable path to the final goal weight than a continuous unbroken push from start to finish.

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Assumptions and Notes

• Margin of error: All four IBW formulas assume average body composition for height and sex and are most accurate for adults of average muscle mass and bone density. The healthy BMI range (18.5–24.9) has established research support for metabolic health at the population level but is less applicable to highly muscular individuals, older adults (for whom 23–27 is a better range), and certain ethnic populations where metabolic risk begins at lower BMI values (23 for South Asian populations per WHO guidelines). Goal weight ranges derived from this calculator should be treated as planning references, not clinical prescriptions.
• Professional disclaimer: Goal weight estimates from this calculator are for informational and planning purposes only and do not constitute medical or dietary advice. People with eating disorder history, significant obesity, metabolic disease, osteoporosis, sarcopenia, or other conditions affecting body composition and weight should set goal weights in consultation with a physician or registered dietitian. Athletes in weight-category sports should work with a sports dietitian to ensure goal weights are safe and performance-compatible.

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The Weight You Are Aiming For

Fatima's goal weight range of 55–60 kg came from three inputs working together: the formula cluster said 54.7–58.8 kg, the healthy BMI range said 49.2–66.2 kg, and her small frame said the lower 35% of that range. The number 68 kg as an intermediate milestone was not from any formula — it came from asking where the first meaningful clinical benefit appears. That question is more useful than any 1964 pharmacology formula.

Tomasz's 76.8 kg stage weight was above every formula output. It had to be. Formulas do not know he has 72.2 kg of lean mass.

Start with the calculator. Then ask whether the output makes sense for the person actually standing on the scale.

Enter your height and current weight above to see your goal weight range now.

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Further Reading

• Weight Loss Calculator: Build a Calorie Deficit Plan to Reach Your Goal Weight Safely
• Weight Loss Percentage Calculator: Track Your Progress Toward Your Goal Weight as a Percentage
• BMI Calculator: See Where Your Current and Goal Weights Sit Within the Healthy BMI Range