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Ideal Weight Calculator — Find Your Ideal Body Weight

Use this free ideal weight calculator to find your ideal body weight range based on your height, gender, and age. This calculator computes ideal body weight using four widely referenced medical formulas — Robinson, Miller, Devine, and Hamwi — and displays all results side by side for easy comparison, along with the healthy weight range based on WHO BMI guidelines. Understanding these ranges gives you a useful reference point for health and fitness goals.

IBW formulas compare height and sex only — they do not measure body composition. Use them as references, not strict targets. Adults 18+: formulas below. Under 18: prefer CDC BMI-for-age with a pediatrician.

Feet and inches.

ages: 2 – 80

Ideal weight estimates will appear here after you calculate.

How to use

  1. Choose US, metric, or other (meters); enter age (2–80) and gender.
  2. Enter height — feet and inches, centimeters, or meters.
  3. Click Calculate to see Robinson, Miller, Devine, Hamwi, and the WHO BMI 18.5–25 weight band in lbs and kg.
  4. Read the educational sections below for frame size, children, and limitations — IBW is a reference, not a prescription.

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How this ideal weight calculator works

Enter your age, gender, and height to see your ideal weight calculated by four established medical formulas simultaneously. Results are displayed side by side so you can see the range across different methodologies. The calculator also shows your healthy weight range based on the WHO's recommended BMI range of 18.5–25 — the widest and most commonly referenced healthy weight guideline. Results are shown in both pounds and kilograms. Toggle between US units, metric units, and height in meters using the tabs above the calculator.

Ideal weight results — what the formulas show

For example, a 5'10" adult male typically sees values in this ballpark (your exact numbers depend on rounding and height entry):

FormulaIdeal weight (approx.)
Robinson (1983)~156.5 lbs
Miller (1983)~155.0 lbs
Devine (1974)~160.9 lbs
Hamwi (1964)~165.3 lbs
Healthy BMI range~128.9 – 174.2 lbs

The four formulas give somewhat different results — which is expected since they were developed independently. The healthy BMI range is broader because it spans BMI 18.5 through 25.

The four ideal weight formulas

All four share the same structure: a base weight at exactly 5 feet tall, plus a fixed increment for each inch above 5 feet. Differences are in the base values and per-inch increments.

G.J. Hamwi (1964)

Developed for medication dosage in clinical settings.

  • Male: 48.0 kg + 2.7 kg per inch over 5 feet
  • Female: 45.5 kg + 2.2 kg per inch over 5 feet

B.J. Devine (1974)

The most widely used IBW formula in clinical practice — anesthesiology, respiratory therapy, and pharmacology still reference it for dosing.

  • Male: 50.0 kg + 2.3 kg per inch over 5 feet
  • Female: 45.5 kg + 2.3 kg per inch over 5 feet

J.D. Robinson (1983)

A modification of Devine using a different dataset.

  • Male: 52 kg + 1.9 kg per inch over 5 feet
  • Female: 49 kg + 1.7 kg per inch over 5 feet

D.R. Miller (1983)

Another Devine modification; compare side by side with Devine and Robinson at your height.

  • Male: 56.2 kg + 1.41 kg per inch over 5 feet
  • Female: 53.1 kg + 1.36 kg per inch over 5 feet

Healthy BMI range (WHO)

BMI 18.5–25 translates to a weight band for any height. This approach acknowledges that healthy weight spans a range rather than a single number.

How much should I weigh?

Ideal body weight formulas were originally developed to improve drug dosage accuracy — not to define aesthetics. Certain drugs are dosed using IBW rather than total weight. IBW later became a general health reference and is also used in sports with weight classes.

No formula can definitively state how much any individual should weigh to be healthy. IBW ignores body fat vs. muscle, genetics, bone density, and health conditions. A muscular athlete may be above formula IBW while being very healthy. Making sustainable choices around activity, nutrition, sleep, and stress matters more than hitting one number from a population equation.

Factors that affect ideal body weight

  • Age: After growth is complete, age has little effect on the equations themselves, but older adults often lose height and lean mass while fat mass can rise — composition changes even when scale weight is similar.
  • Gender: Formulas use different bases for men and women, reflecting average differences in muscle, bone, and stature.
  • Height: The primary driver in every IBW formula.
  • Body frame size: Standard formulas assume a medium frame. Wrist circumference vs. height helps estimate small, medium, or large frame (see below).

Body frame size — women

  • Under 5'2": small < 5.5" wrist; medium 5.5"–5.75"; large > 5.75"
  • 5'2"–5'5": small < 6"; medium 6"–6.25"; large > 6.25"
  • Over 5'5": small < 6.25"; medium 6.25"–6.5"; large > 6.5"

Body frame size — men

Commonly cited guidance for men over 5'5":

  • Small: wrist 5.5"–6.5"
  • Medium: wrist 6.5"–7.5"
  • Large: wrist over 7.5"

Healthy BMI weight range by height

Approximate weight bands for BMI 18.5–25 (rounded):

HeightHealthy weight range (approx.)
5'0"97 – 127 lbs
5'2"104 – 136 lbs
5'4"110 – 144 lbs
5'6"118 – 154 lbs
5'8"125 – 163 lbs
5'10"132 – 173 lbs
6'0"140 – 183 lbs
6'2"148 – 194 lbs

Use the calculator for your exact height; table values are illustrative.

Ideal weight for children and teens

The adult IBW formulas apply to adults 18 and older. For children and adolescents, clinicians use BMI-for-age percentiles on CDC growth charts (typically aiming between the 5th and 85th percentile for age and sex). A pediatrician can plot trends over time — a single point is less informative than the growth pattern.

Limitations of ideal weight formulas

  • They use only height and gender — not composition, frame, ethnicity, disability, or training status.
  • They were built for dosing, not for appearance or self-worth.
  • Very muscular people often read "over" formula IBW while being metabolically healthy.
  • Linear formulas can be less satisfying at very short or very tall extremes; the BMI band is sometimes a practical cross-check.

A more complete picture of healthy weight

Alongside IBW and BMI, many clinicians consider waist circumference, body fat percentage, waist-to-hip ratio, blood pressure, lipids, and blood sugar. For next steps, see our BMI Calculator, Body Fat Calculator, and Calorie Calculator.

Frequently asked questions

IBW formulas, BMI range, frame size, and how to use these numbers.

How much should I weigh for my height?

There is no single correct answer — healthy weight for a given height spans a range depending on body composition, frame size, age, and gender. As a general reference, the WHO healthy BMI range of 18.5–25 translates into a practical weight range for any height. For a 5'6" woman this is approximately 115–154 lbs. For a 5'10" man approximately 132–174 lbs. Use the calculator above to see both the formula-based IBW and the healthy BMI range for your specific height and gender.

What is ideal body weight (IBW)?

Ideal body weight is a reference weight calculated from height and gender using one of several established medical formulas. IBW was originally developed to facilitate drug dosage calculations in clinical medicine — certain medications are dosed based on IBW rather than total body weight. It has since been adopted as a general health reference. The most commonly used IBW formula is the Devine formula, though several variations exist. IBW should be understood as a reference estimate, not a precise target or health standard.

Is it possible to be healthy above your ideal body weight?

Absolutely. IBW formulas only account for height and gender — they cannot assess body composition, fitness level, or actual health status. Muscular individuals are frequently above their formula-calculated IBW while having excellent health metrics. Conversely someone can be within their IBW range while having poor body composition (high fat, low muscle), metabolic disease, or poor cardiovascular fitness. Health is better assessed through body composition, fitness, and metabolic markers than through weight alone.

Which ideal weight formula is most accurate?

The Devine formula is the most widely used in clinical medicine and is generally considered the standard reference. The Robinson formula is a commonly used modification. The Miller formula is another Devine modification that can differ from Devine depending on height. The Hamwi formula, the oldest, is still used in some clinical settings. No single formula is definitively most accurate for all individuals — the range across formulas gives a better sense of reasonable ideal weight than any single formula alone. The healthy BMI range is arguably the most evidence-based reference since it is derived from large studies linking BMI to health outcomes.

How do I know if I have a small, medium, or large frame?

Frame size is estimated using wrist circumference relative to height. For women under 5'2": small frame is below 5.5" wrist, medium is 5.5"–5.75", large is above 5.75". For women 5'2"–5'5": small below 6", medium 6"–6.25", large above 6.25". For women over 5'5": small below 6.25", medium 6.25"–6.5", large above 6.5". For men over 5'5": small 5.5"–6.5", medium 6.5"–7.5", large above 7.5". Large-framed individuals naturally weigh more than small-framed individuals at the same height — all IBW formulas assume medium frame.

What is the ideal weight for women by height?

Using the Devine formula — the most widely used clinical standard — ideal weights for women are approximately: 5'0" ≈ 100 lbs, 5'2" ≈ 104 lbs, 5'4" ≈ 109 lbs, 5'6" ≈ 114 lbs, 5'8" ≈ 118 lbs, 5'10" ≈ 123 lbs, 6'0" ≈ 128 lbs. The healthy BMI range gives a broader window — for a 5'6" woman this is approximately 115–154 lbs. Use the calculator above for precise results at your specific height.

What is the ideal weight for men by height?

Using the Devine formula — the most widely used clinical standard — ideal weights for men are approximately: 5'6" ≈ 61 kg (135 lbs), 5'8" ≈ 66 kg (145 lbs), 5'10" ≈ 71 kg (156 lbs), 6'0" ≈ 75 kg (166 lbs), 6'2" ≈ 80 kg (176 lbs). The healthy BMI range for a 5'10" man is approximately 132–174 lbs. Use the calculator above for precise results at your specific height.

Should I try to reach my ideal body weight?

IBW provides a general reference point — not a specific weight you must achieve to be healthy. Many people are perfectly healthy above or below their formula-calculated IBW. Rather than focusing on reaching a specific weight number, focus on sustainable healthy behaviors: regular physical activity including both cardio and strength training, eating primarily whole unprocessed foods, maintaining adequate sleep, and managing stress. These behaviors improve health independent of the specific weight you achieve.

How does frame size affect ideal weight?

Frame size significantly affects what's an appropriate weight for any given height. A large-framed individual has denser, heavier bones and typically more muscle mass than a small-framed person of the same height. Standard IBW formulas assume medium frame — large-framed people may be perfectly healthy at weights 10–15% above the formula result, while small-framed individuals may be healthy at 10–15% below. Measuring your wrist circumference and comparing it to the frame size guidelines above gives you a sense of whether the standard formula applies to you or needs adjustment.

Who uses this calculator

This ideal weight calculator is used by people who want a general reference for healthy weight at their height, individuals beginning a weight loss journey who want to understand a reasonable target, healthcare students and professionals learning about IBW formulas used in clinical dosage calculations, athletes checking where their weight falls relative to general population references, parents checking reference points for their children's growth development, and anyone who has wondered whether their current weight falls within a clinically referenced healthy range for their height and gender.