Calculate your ideal body weight using Devine, Hamwi, Robinson, and Miller formulas — adjusted for height, gender, and body frame size. Includes Adjusted Body Weight (ABW), BMI target, and progress tracking.
Enter height in centimeters (e.g. 170 cm)
Not sure? Wrap your thumb and middle finger around your wrist. Overlap = small frame. Touch = medium. Gap = large.
Adjusts time-to-goal estimate
Enables ABW & progress
Track your health and fitness goals.
Select Gender and Units: Choose male or female and your preferred unit system: metric (kg/cm) or imperial (lbs/in).
Enter Height: Enter your height in cm (metric) or inches (imperial). Valid range: 147–213 cm (58–84 in).
Determine Frame Size: Measure wrist circumference to determine frame size. Women: under 14 cm small, 14–16.5 cm medium, over 16.5 cm large. Men: under 16.5 cm small, 16.5–19 cm medium, over 19 cm large.
Enter Current Weight (Optional): Enter your current weight to see your difference from IBW, Adjusted Body Weight (ABW), and time-to-goal estimate.
Review Results: View your ideal weight from all four formulas, the healthy range, target BMI, and ABW. Use the formula selector to see a step-by-step calculation breakdown.
Uses four popular formulas including Robinson, Miller, Devine, and Hamwi to estimate ideal body weight.
Separate formulas for men and women provide more accurate ideal weight estimates.
Adjusts ideal weight estimates based on small, medium, or large body frame size.
Shows a recommended healthy weight range based on BMI and height.
Compare results from different formulas in a clear chart to understand variations.
Visual charts help you quickly see where your current weight falls within the healthy range.
Provides guidance based on BMI categories to help you understand whether you are underweight, healthy, overweight, or obese.
Body frame size is not estimated by appearance — it is measured by skeletal dimensions that do not change with weight fluctuation. Two clinically accepted methods exist: the wrist circumference method (quick and practical) and the elbow breadth method (more precise, used in clinical settings).
| Frame | Women | Men |
|---|---|---|
| Small | < 14 cm / 5.5″ | < 16.5 cm / 6.5″ |
| Medium | 14–16.5 cm / 5.5–6.5″ | 16.5–19 cm / 6.5–7.5″ |
| Large | > 16.5 cm / 6.5″ | > 19 cm / 7.5″ |
Elbow breadth is used in NHANES population studies and is considered more reliable than wrist circumference because it is less affected by soft tissue.
Quick check (no measuring tape): Wrap your thumb and middle finger around your opposite wrist. If they overlap — small frame. If they just touch — medium frame. If there is a gap — large frame. This is a rough guide; formal measurement is more accurate.
The four IBW formulas can produce results that differ by 5–15 lbs (2–7 kg) for the same person. This is not a calculation error — it reflects the different populations and purposes each formula was designed for. Understanding why they differ helps you choose the most relevant result for your situation.
Developed by Dr. G.J. Hamwi for estimating ideal body weight in diabetes nutrition planning. The base weight of 48 kg (men) / 45.5 kg (women) was derived from actuarial insurance tables of the era. Its higher multiplier of 2.7 kg per inch (men) tends to produce the highest IBW estimates among the four formulas.
Best used for: Dietitians, diabetes educators, clinical nutrition assessments.
Published by Dr. B.J. Devine in a pharmacology context, this formula was originally designed for calculating drug doses — not to define the healthiest weight. Its base of 50 kg (men) / 45.5 kg (women) with 2.3 kg per inch became the de facto clinical standard because medication dosing manuals adopted it widely.
Best used for: Pharmacy dosing (tidal volume, aminoglycosides, creatinine clearance), general clinical practice.
Dr. J.D. Robinson et al. analyzed the Devine formula and found it overestimated IBW for shorter individuals. The Robinson formula uses lower multipliers (1.9 kg/inch men, 1.7 kg/inch women) and tends to produce the lowest estimates — more conservative, leaning toward lighter reference weights.
Best used for: Pharmaceutical references where conservative estimates are preferred.
Also published in 1983, Dr. R.K. Miller's formula uses a higher base weight (56.2 kg men / 53.1 kg women) with a lower multiplier (1.41/1.36 kg per inch), meaning it gives relatively higher estimates for shorter people but converges with other formulas at taller heights.
Best used for: Alternative clinical reference; sometimes preferred for older adult populations.
Bottom line: No single formula is universally "correct." The average of all four gives the most balanced estimate. Clinicians choose specific formulas based on their application: Devine for drug dosing, Hamwi for nutrition, Robinson where conservative estimates are needed. For general health awareness, the average or range is most meaningful.
When a patient's actual body weight significantly exceeds their ideal body weight (IBW), pharmacists and physicians do not use actual weight or IBW alone for drug dosing calculations. Instead, they use Adjusted Body Weight (ABW) — a middle-ground value that accounts for the fact that obese individuals have expanded blood volume, altered tissue distribution, and greater lean mass than predicted by IBW alone.
ABW = IBW + 0.4 × (Actual Body Weight − IBW)
The correction factor of 0.4 (40%) is derived from studies showing that obese patients distribute lipophilic drugs based on approximately 40% of their excess weight beyond IBW.
Actual Body Weight: Used for weight-based dosing when the patient is at or below IBW, or for drugs with poor fat solubility.
IBW: Used directly for lung-protective ventilation and some renal function estimates (Cockcroft-Gault for CrCl).
ABW: Used for lipophilic drugs in patients >30% above IBW.
Note: If you entered your current weight above and it exceeds your IBW, this calculator automatically displays your ABW in the results section for reference. This is educational information — always consult a pharmacist or physician for any medication dosing decisions.
IBW formulas and BMI are both height-based weight assessments, but they were developed for different purposes, use different mathematical models, and are most useful in different contexts. Many people use them interchangeably — which leads to confusion. Here is a precise comparison.
| Factor | Ideal Body Weight (IBW) | Body Mass Index (BMI) |
|---|---|---|
| Formula type | Linear (weight per inch above 5 ft) | Ratio (weight ÷ height²) |
| Considers gender | Yes — separate formulas for male/female | No — same formula for all genders |
| Considers frame size | Yes — ±10% adjustment for small/large frame | No — single value for all frame sizes |
| Output | A target weight range in kg or lbs | A dimensionless index number |
| Primary clinical use | Drug dosing, ventilator settings, nutrition | Population-level obesity screening |
| Accuracy for athletes | Poor — does not account for muscle mass | Poor — overestimates adiposity in athletes |
| Accuracy for elderly (65+) | Moderate — may overestimate ideal weight | Moderate — weight cutoffs may be too low |
| Developed from | Clinical and pharmacological populations (1960s–80s) | Belgian population statistics (Quetelet, 1830s) |
| Best used for | Individual weight targets, clinical dosing reference | Broad population screening, insurance risk stratification |
Which should you use? Use IBW when you want a specific weight target that accounts for your gender and frame. Use BMI for a quick screening assessment or to compare with population norms. For the most complete picture, combine both with a body fat percentage measurement — especially if you are athletic, elderly, or have significant muscle mass.
The IBW formulas in this calculator were derived from studies of young to middle-aged adults. They do not automatically adjust for age-related changes in body composition, bone density, or health risk profiles. Understanding how ideal weight considerations shift across age groups prevents misinterpretation of results.
IBW formulas are not validated for children and teens. Growing bodies have different fat-to-muscle-to-bone ratios at every developmental stage. The appropriate tool is the CDC BMI-for-age percentile chart (ages 2–19), which classifies weight relative to peers of the same age and sex. A child at the 50th percentile is considered a healthy weight. Percentiles below the 5th or above the 95th warrant pediatric evaluation. Never use adult IBW formulas for anyone under 18.
This is the population group closest to the original derivation samples. IBW formulas are most accurate here. Muscle development from exercise is the main variable that can cause someone to healthily exceed their calculated IBW — a 25-year-old male athlete with 10% body fat may be 10–20 lbs above his Devine formula result yet be in excellent health.
Metabolic rate decreases ~2–3% per decade after 25. Muscle mass naturally declines (sarcopenia begins around 35). This means the same calculated IBW becomes progressively harder to maintain with the same diet. It also means that someone at their "ideal weight" in this age group may have a higher body fat percentage than a younger person at the same weight — making body composition analysis increasingly important.
Research consistently shows that for adults over 65, the relationship between weight and mortality differs from younger populations. Multiple large cohort studies have found that older adults at the higher end of the "overweight" BMI range (25–29.9) have better survival outcomes than those at "normal" BMI — a phenomenon called the obesity paradox.
For older adults, the standard IBW formula may suggest a target weight that is actually too low for optimal health. Key reasons include: muscle mass loss accelerates with aggressive caloric restriction; weight loss in the elderly is often accompanied by bone density loss; modest excess weight provides metabolic reserve during illness. Older adults should not pursue aggressive weight loss toward standard IBW targets without physician guidance.
Determining ideal weight for children is fundamentally different from adults. While adult formulas like Devine and Hamwi rely on fixed calculations, children's healthy weight depends on age, height, and individual growth patterns tracked over time. Rather than using a single target number, healthcare providers assess children using BMI-for-age percentile charts.
The CDC and WHO recommend using age and gender-specific BMI percentiles for children aged 2–19 years. A child at the 50th percentile is considered at a healthy weight for their age group. These percentiles recognize that children grow at different rates, and what's healthy for one 10-year-old may differ from another based on their individual growth trajectory.
Applying adult IBW formulas to children can be misleading and potentially harmful. Growing bodies require adequate nutrition to develop properly, and restrictive thinking about weight during childhood can contribute to disordered eating patterns. If you're concerned about a child's weight, consulting with a pediatrician who can evaluate growth charts, developmental stage, and overall health is always the appropriate approach.
Being above your ideal weight number doesn't automatically mean you're unhealthy. Weight is just one indicator, and multiple assessment methods provide a more complete picture.
Consider the complete picture rather than focusing solely on a single weight number.
While ideal weight formulas based on height and gender provide useful reference points, they don't account for body composition differences. Two people of the same height and weight can have dramatically different health profiles depending on their muscle-to-fat ratio.
Example: A 5′10″ male at 190 lbs could be an athlete with 10% body fat (mostly muscle) or have 35% body fat. Both weigh the same but their health status is entirely different. The athlete may healthily exceed his IBW; the second person may need to address fat mass despite appearing close to target.
Healthy body fat ranges (general guidelines):
Maintaining a healthy weight is about sustainable lifestyle habits rather than perfect adherence to a number.
Choose Stairs Instead of Elevators
Climbing stairs for 15 minutes daily burns ~100 extra calories and strengthens leg muscles. Over a year, this habit alone could prevent 10+ lbs of weight gain.
Balance Meals, Don't Restrict Severely
Eat protein with every meal (keeps you fuller longer), include vegetables and whole grains, and allow small amounts of foods you enjoy. Sustainability beats perfection.
Prioritize Consistency Over Perfection
Making healthy choices 80% of the time is far more effective than being perfect for a week then abandoning all effort.
Move Your Body Daily
Any activity counts — walking, gardening, dancing, sports. Aim for at least 150 minutes per week of moderate movement.
Hydrate Consistently
Dehydration is often mistaken for hunger. Drinking water before meals supports portion control and metabolic function.
Prioritize Sleep (7–9 Hours)
Poor sleep disrupts ghrelin and leptin (hunger hormones) and increases cravings for high-calorie foods by up to 45%.
This calculator uses four peer-reviewed formulas. Each formula uses gender, height in inches, and a linear model to calculate IBW. A ±10% frame size adjustment is applied: small frame ×0.9, large frame ×1.1, medium frame ×1.0 (no adjustment). Results are always presented in kg; imperial display converts via 1 kg = 2.20462 lbs.
Originally developed for medication dosing calculations in clinical pharmacology. Most widely referenced in drug dosing literature.
Male: IBW = 50 + 2.3 × (inches over 60)
Female: IBW = 45.5 + 2.3 × (inches over 60)
Developed for estimating ideal body weight in clinical nutrition and diabetes management. Standard in dietetics practice.
Male: IBW = 48 + 2.7 × (inches over 60)
Female: IBW = 45.5 + 2.2 × (inches over 60)
A refinement of the Devine formula for improved accuracy, particularly for shorter height ranges.
Male: IBW = 52 + 1.9 × (inches over 60)
Female: IBW = 49 + 1.7 × (inches over 60)
Alternative height-based calculation validated for clinical use, with a higher base weight and lower per-inch multiplier.
Male: IBW = 56.2 + 1.41 × (inches over 60)
Female: IBW = 53.1 + 1.36 × (inches over 60)
The table below shows ideal weight ranges for adult males and females at each height, calculated as the average of all four formulas (Devine, Hamwi, Robinson, Miller) at medium frame size. Small frame individuals subtract ~10%; large frame individuals add ~10%.
| Height (ft/in) | Height (cm) | Male (lbs) | Female (lbs) | Male (kg) | Female (kg) |
|---|---|---|---|---|---|
| 4′10″ | 147 | 88-112 | 83-106 | 40-51 | 38-48 |
| 5′0″ | 152 | 97-123 | 92-115 | 44-56 | 42-52 |
| 5′2″ | 157 | 107-135 | 101-128 | 49-61 | 46-58 |
| 5′4″ | 163 | 117-148 | 110-139 | 53-67 | 50-63 |
| 5′6″ | 168 | 128-162 | 120-151 | 58-73 | 54-69 |
| 5′8″ | 173 | 139-176 | 130-164 | 63-80 | 59-74 |
| 5′10″ | 178 | 150-190 | 141-177 | 68-86 | 64-80 |
| 6′0″ | 183 | 162-205 | 152-191 | 73-93 | 69-87 |
| 6′2″ | 188 | 174-220 | 164-205 | 79-100 | 74-93 |
| 6′4″ | 193 | 187-236 | 176-220 | 85-107 | 80-100 |
Values represent average of Devine, Hamwi, Robinson, and Miller formulas at medium frame. Range reflects small (−10%) to large (+10%) frame variation. These are estimates, not medical diagnoses.
IBW formulas have known limitations for specific populations. These are not edge cases — they are common:
Athletes & Bodybuilders
High muscle mass increases weight beyond typical ranges. Body composition analysis (DEXA, BIA, calipers) is more accurate than any formula.
Pregnant Women
Weight gain during pregnancy is medically necessary. IBW formulas should not be used during any stage of pregnancy. Consult your OB/GYN for trimester-specific guidelines.
Adults 65+
Standard IBW may suggest targets that are too low for older adults. Research supports slightly higher weights for longevity in this group (obesity paradox).
Children & Adolescents
IBW formulas are not validated for anyone under 18. Use CDC BMI-for-age percentile charts for pediatric weight assessment.
People of Asian Descent
WHO and several national health bodies recommend lower BMI thresholds for Asian populations (overweight: BMI ≥23, obese: BMI ≥27.5). IBW formulas do not adjust for ethnicity.
Individuals with Limb Differences
Height-based formulas assume full limb presence. Adjusted calculations exist for amputees — consult a clinical dietitian for accurate IBW in these cases.
Important: These results represent reference ranges, not medical diagnoses. Always consult a qualified healthcare provider before making weight-related health decisions, especially if you have a chronic condition, are on medications, are pregnant, or are over 65.
Content last updated: November 2025
The calculations and formulas used in this ideal weight calculator are based on well-known clinical research formulas including the Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964) methods. These formulas are commonly referenced in clinical pharmacology, nutrition science, and medical literature.
Medical Disclaimer: This calculator is provided for general informational and educational purposes only. It should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional for personalized health guidance.
Ideal body weight (IBW) is a target weight range calculated from a person's height and gender using clinically validated formulas. Originally developed for clinical drug dosing, it has become a general health reference.
No single formula is universally most accurate. The Devine formula is most widely used clinically, Hamwi is common in nutrition practice, Robinson produces conservative estimates, and Miller tends to produce slightly higher weights.
Each IBW formula was derived from different populations and decades for different clinical purposes. Because of this, results can vary slightly and typically define a healthy range rather than a single exact weight.
Adjusted Body Weight (ABW) is calculated as IBW + 0.4 × (Actual Body Weight − IBW). It is used by clinicians when a person's actual weight is significantly above their ideal body weight.
IBW formulas generally do not account for muscle mass. Athletes with high lean muscle may weigh more than their calculated IBW while still being healthy.
Body frame size reflects skeletal structure. Larger frames can support more weight while smaller frames typically require less weight.
For a 5 foot 4 inch (163 cm) female with a medium frame, ideal weight is generally around 110–139 lbs (50–63 kg) depending on the formula used.
For a 6 foot (183 cm) male with a medium frame, ideal weight is roughly 162–205 lbs (73–93 kg) depending on the formula.
IBW and BMI healthy weight are related but calculated differently. IBW uses formulas based on height and gender, while BMI uses a weight-to-height ratio.
Yes. Ideal weight alone does not determine health. Body fat percentage, metabolic health, diet, and physical fitness all play important roles.