Ideal Weight Calculator

Last updated: May 2026

Find your healthy weight range using 5 scientifically validated formulas — plus your BMI-based range and how far you are from each target.

Your Measurements

Your Ideal Weight Results

Average (All Formulas)
consensus target
BMI Range (18.5–24.9)
WHO standard
Difference from Average
FormulaIdeal WeightMethodDifference from You
Your Current Position
UnderweightIdealOverweightObese

Hamwi (1964): Men: 48 kg + 2.7 kg per inch over 5ft. Women: 45.5 kg + 2.2 kg per inch over 5ft. One of the most widely used in clinical settings.

Devine (1974): Men: 50 kg + 2.3 kg/inch. Women: 45.5 kg + 2.3 kg/inch over 5ft. Originally developed for medication dosing, widely adopted as a general IBW formula.

Robinson (1983): Men: 52 kg + 1.9 kg/inch. Women: 49 kg + 1.7 kg/inch over 5ft. Slight variation accounting for frame differences.

Miller (1983): Men: 56.2 kg + 1.41 kg/inch. Women: 53.1 kg + 1.36 kg/inch over 5ft. Tends to produce higher ideal weights for taller individuals.

BMI Range: The healthy BMI range (18.5–24.9) translated to weight for your height. The widest range — acknowledges that a single ideal weight is arbitrary.

Important: No single ideal weight formula is definitive. Muscle mass, bone density, age, and ethnicity all affect what "ideal" means for you. Use these as ranges, not exact targets.

⚠️ Ideal weight formulas are population-based estimates and do not account for muscle mass, body composition, or individual health status. Consult a healthcare provider for personalized weight guidance.

How the Ideal Weight Calculator Works

This calculator computes your healthy weight range using five established scientific formulas, each developed through different research methodologies.

Hamwi: Men: 48 kg + 2.7 kg/inch over 5ft | Women: 45.4 kg + 2.27 kg/inch over 5ft Devine: Men: 50 kg + 2.3 kg/inch over 5ft | Women: 45.5 kg + 2.3 kg/inch over 5ft Robinson: Men: 52 kg + 1.9 kg/inch over 5ft | Women: 49 kg + 1.7 kg/inch over 5ft Miller: Men: 56.2 kg + 1.41 kg/inch over 5ft | Women: 53.1 kg + 1.36 kg/inch over 5ft

The BMI range method (18.5-24.9) gives a range rather than a single number, accommodating natural body size variation. The four formula-based methods give point estimates originally developed for clinical drug dosing — they provide a useful reference but no single formula is universally applicable.

Worked example (5'8" man): Hamwi: 48 + (2.7 x 8) = 69.6 kg (153 lbs). Devine: 50 + (2.3 x 8) = 68.4 kg (151 lbs). BMI range: 125-164 lbs. The range (125-164) is more clinically useful than any single point estimate.

Frequently Asked Questions

Which ideal weight formula is most accurate?

No single formula is universally most accurate — they were developed for different purposes and populations. The Devine formula is most commonly used in clinical medicine for drug dosing. The BMI range (18.5-24.9) provides the broadest healthy weight range and is endorsed by the WHO and CDC. For personal health goals, the BMI range is the most practical reference since it accounts for natural variation in body composition among people of the same height.

Does ideal weight differ for men and women?

Yes — all five formulas differentiate by sex because men typically have greater bone density, muscle mass, and organ weight than women of the same height. At 5'8", the Devine formula suggests 151 lbs for men and 137 lbs for women. The BMI-based range is the same for both sexes since BMI itself does not account for sex differences, which is one of its known limitations.

Is there a single ideal weight I should target?

Health professionals generally recommend targeting a range rather than a single number. The BMI 18.5-24.9 range for a 5'8" person spans 125-163 lbs — a 38-pound window. Within that range, factors like muscle mass, bone structure, and how you feel physically matter more than hitting a specific number. Many fit, healthy people fall slightly outside these ranges in either direction.

Can I be at a healthy weight but still be unhealthy?

Yes — weight alone is not a complete health measure. Metabolic syndrome (characterized by high blood pressure, blood sugar, triglycerides, and waist circumference) can occur at "normal" weight. Conversely, some people with BMI in the "overweight" range are metabolically healthy. Waist-to-height ratio (waist circumference divided by height; healthy below 0.5) and waist-to-hip ratio are additional useful measures alongside BMI and weight.

How Ideal Weight Formulas Compare

The concept of "ideal body weight" originated not in fitness culture but in clinical medicine — specifically, to calculate drug dosages more accurately than total body weight allows. The four most widely cited formulas were published between 1964 and 1983, each using slightly different baseline assumptions for height and sex. None was designed as a personal health target; all are better understood as reference ranges for clinical estimation.

Body weight norms have evolved considerably since these formulas were derived, and modern research favors ranges over point estimates. The BMI 18.5–24.9 band, endorsed by the WHO and CDC, captures the broad middle of healthy weight for a given height rather than prescribing a single number. For most people, the lower and upper bounds of that range differ by 30–40 lbs — a spread that reflects genuine biological diversity rather than measurement error.

FormulaMen (5'10")Women (5'4")Notes
Devine (1974)178 lbs120 lbsMost cited in medicine
Robinson (1983)174 lbs126 lbsModified Devine
Miller (1983)170 lbs122 lbsMore conservative
Hamwi (1964)166 lbs120 lbsOldest formula
BMI 22 midpoint172 lbs128 lbsBMI-based target
Healthy BMI range145–185 lbs108–145 lbs18.5–24.9 BMI

Worked Examples

Example 1 — Devine formula for a 5'10" male
The Devine formula is: 50 kg + 2.3 kg for every inch over 5 feet. A 5'10" man is 10 inches over 5 feet, so: 50 + (2.3 × 10) = 50 + 23 = 73 kg = 161 lbs. This is a useful clinical starting point for drug dosing — but it is not a prescription. Muscle mass, bone density, and body composition all affect what a healthy weight looks like for any individual. Two men who are both 5'10" and 161 lbs can have very different health profiles depending on how that weight is distributed between muscle and fat.
Example 2 — Healthy BMI weight range for a 5'6" woman
Height in meters: 5'6" = 1.68 m. Lower bound (BMI 18.5): 18.5 × (1.68)² = 18.5 × 2.8224 = 52.2 kg = 115 lbs. Upper bound (BMI 24.9): 24.9 × (1.68)² = 24.9 × 2.8224 = 70.3 kg = 155 lbs. The healthy range spans 115–155 lbs — a 40-lb window. This illustrates exactly why a single "ideal weight" number is misleading: a 5'6" woman who weighs 130 lbs and one who weighs 150 lbs can both be equally healthy. The range is the answer, not a point on the scale.

Frequently Asked Questions

Is there one ideal weight that applies to everyone?

No. Ideal weight formulas give estimates based on height and sex, but they don't account for muscle mass, bone density, age, or body composition. A range — like the BMI 18.5–24.9 band — is more meaningful than any single number. Two people at the same height and weight can have very different body compositions and health outcomes.

Which ideal weight formula is most accurate?

No single formula outperforms the others for general use. The Devine formula is the most widely used in clinical medicine (primarily for drug dosing), but all four formulas were derived from older, less diverse populations. For personal health goals, the healthy BMI range (18.5–24.9) is the most evidence-based reference and is endorsed by the WHO and CDC.

Does ideal weight change with age?

The standard formulas don't adjust for age, but body composition naturally shifts with aging — muscle mass tends to decrease and fat tends to increase even at a stable weight. Some research suggests that slightly higher BMI (up to 27) may be associated with better outcomes in adults over 65. Always discuss weight targets with a healthcare provider, especially for older adults.

How does frame size affect ideal weight?

Frame size (wrist circumference relative to height) is sometimes used to adjust ideal weight estimates by 10% in either direction — smaller frames toward the lower end of the range, larger frames toward the upper end. However, this adjustment is informal and not validated by large clinical studies. The BMI range already accommodates most frame size variation within its 30–40 lb spread for any given height.

Is ideal weight the same as goal weight?

Not necessarily. Ideal weight is a statistical reference derived from population health data. Goal weight is personal — it reflects what weight you feel best at, can sustain long-term, and allows you to meet your health or fitness objectives. Your goal weight may fall anywhere within the healthy range, or your doctor may recommend a specific target based on your individual health history.