Ideal Weight Calculator
Your ideal body weight by four formulas, plus the healthy-BMI range
🎯 Your details
Last updated June 2026
Method: Ideal body weight is computed with the four published equations - Devine (1974), Robinson (1983), Miller (1983) and Hamwi (1964) - using a base weight at 5 ft of height plus a per-inch increment. The healthy-weight range uses the standard BMI band of 18.5–24.9.
Included: Separate estimates for men and women, all four formulas with their average, imperial (lb, ft/in) and metric (kg, cm) units, and a BMI-based healthy weight range.
Not included: Muscle mass, body-fat percentage, frame size, age and pregnancy. This is an estimate, not medical advice - consult a doctor or registered dietitian before setting a goal weight.
Ideal weight calculator: how to read your number
For a woman who is 5 feet 6 inches tall, the four classic formulas land between roughly 129 and 135 pounds, for an average near 131 lb - while the healthy-BMI range for that height runs from about 115 to 154 lb. That spread is the whole point: there is no single "ideal" weight. This ideal weight calculator shows every formula side by side so you can see the range instead of fixating on one number.
How ideal body weight is calculated
Each formula starts from a base weight at 5 feet of height and adds a fixed amount for every inch above that. The most widely used is the Devine formula:
Men: 50 kg + 2.3 kg × (inches over 5 ft)
Women: 45.5 kg + 2.3 kg × (inches over 5 ft) The Robinson, Miller and Hamwi formulas use the same shape with different base weights and per-inch increments. The result is converted to pounds (1 kg ≈ 2.205 lb). Because each was derived from different data, they disagree by several pounds - so this calculator reports the average of all four alongside the individual values.
Why there are four different formulas
The Hamwi equation (1964) came first, created to estimate insulin dosing. Devine (1974) refined it for drug dosing and is now the clinical standard. Robinson and Miller (both 1983) re-fit the relationship to other population data; Miller tends to read slightly higher, Robinson slightly lower. None is "the right one" - seeing all four is more honest than picking a single equation.
Ideal weight vs. the healthy-BMI range
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases defines a healthy weight using body mass index: a BMI of 18.5 to 24.9 is the normal range. Converting that band back to pounds for your height gives a realistic target window. For most people the healthy-BMI range is a better goal than a single formula number, because it acknowledges that many weights can be healthy at the same height.
Where these numbers fall short
- Muscle: muscle is denser than fat, so athletes often weigh above their "ideal weight" while being very lean.
- Frame size: the formulas assume an average build and can misjudge small or large frames.
- Age & composition: two people at the same weight can have very different body-fat levels.
- Extremes of height: accuracy drops well below 5 ft and at very tall heights.
For a fuller picture, pair this with a body-fat estimate or a lean body mass figure.
How to use this calculator
You only need two pieces of information to get a result. Work through the fields in order:
- Choose your sex: the formulas use a lower base weight for women than for men, so this changes every estimate.
- Pick your units: switch between imperial (feet/inches, pounds) and metric (centimeters, kilograms). The calculator always shows both so you can sanity-check the conversion.
- Enter your height: type your height in the selected units. Be precise - a single inch shifts the Devine estimate by about 2.3 kg (roughly 5 lb).
- Read the output: the tool returns all four formula estimates, their average, and the healthy-BMI weight range for your height.
There is nothing to submit - the numbers update as you type. Try a height an inch higher or lower to see how sensitive the result is, and compare the four-formula average against the wider BMI range to set realistic expectations.
Who this calculator is for
An ideal-weight estimate is a useful reference point for several different people:
- Anyone setting a weight goal who wants a sensible target window rather than a number plucked from the air.
- People starting a weight-loss or weight-gain plan who need a healthy destination range to aim for.
- Curious users comparing their current weight against a height-based reference.
- Anyone learning the difference between the old clinical IBW formulas and the modern BMI range.
It is not designed for children, teenagers, pregnant women, or competitive athletes, whose healthy weight is judged by different methods (growth percentiles, clinical guidance, or body composition).
A second worked example: a 5'10" man
Take a man who is 5 feet 10 inches (70 inches) tall - that is 10 inches over the 5-foot base. Using the Devine formula: 50 kg + (2.3 kg × 10) = 73 kg, or about 161 lb. The Robinson and Miller formulas read a little lower and Hamwi a little higher, so the four-formula average lands near 159 lb. Meanwhile the healthy-BMI range for 5'10" runs from roughly 129 to 174 lb. Notice that the single "ideal" number sits in the upper half of the BMI band - another reminder that the range, not the point estimate, is the realistic target.
Ideal weight by height: a quick reference
People most often search for an ideal weight at a specific height, so here is roughly where the four-formula average lands for common heights. These figures are the average of the Devine, Robinson, Miller and Hamwi estimates, rounded to the nearest pound - your own result may differ by a few pounds, and the healthy-BMI window is always far wider.
- Ideal weight for 5'0" (152 cm): about 106 lb for women and 114 lb for men.
- Ideal weight for 5'4" (163 cm): about 123 lb for women and 132 lb for men.
- Ideal weight for 5'6" (168 cm): about 131 lb for women and 141 lb for men.
- Ideal weight for 5'8" (173 cm): about 140 lb for women and 150 lb for men.
- Ideal weight for 5'10" (178 cm): about 148 lb for women and 159 lb for men.
- Ideal weight for 6'0" (183 cm): about 156 lb for women and 169 lb for men.
Treat these as ballpark anchors, not targets. A 5'6" person, for instance, has a healthy-BMI range of roughly 115 to 154 lb, so the single "ideal" figure of about 131 lb sits comfortably inside a 40-pound band of healthy weights. Enter your exact height above for the precise numbers, and remember that the formulas only know your height and sex - not your muscle, frame or body composition.
Why men and women get different numbers
Every one of these equations applies a lower base weight for women than for men at the same height, then adds the same per-inch increment above 5 feet. The Devine base, for example, is 50 kg for men versus 45.5 kg for women, with 2.3 kg added per inch over 5 ft for both. That 4.5 kg (about 10 lb) head start for men reflects average differences in body composition: men typically carry more lean muscle and denser bone mass, while women carry a higher proportion of essential body fat. The gap is an average, not a rule - a muscular woman can easily out-weigh a lean man of the same height and both be perfectly healthy. If your build does not match the "average" the formula assumes, lean on a body-composition measure rather than the height-and-sex estimate. Our BMR Calculator and TDEE Calculator apply the same sex-based adjustment to estimate the calories your body needs, and the Calorie Calculator turns that into a daily target for reaching a weight inside your healthy range.
Key terms explained
- Ideal body weight (IBW): a single reference weight for a given height and sex, originally built for drug dosing and insurance tables - not a personal fitness mandate.
- Body mass index (BMI): weight in kilograms divided by height in meters squared. A BMI of 18.5–24.9 defines the normal-weight range.
- Lean body mass: everything in your body except fat - muscle, bone, organs and water. Two people at the same weight can have very different lean mass.
- Frame size: your skeletal build (small, medium, large). The classic formulas assume a medium frame and do not adjust for it.
- Adjusted body weight: a clinical tweak that blends ideal and actual weight, sometimes used in dosing for people well above their IBW.
Factors that change your healthy weight
Two people of the same height can both be healthy at quite different weights. The biggest factors the formulas cannot see include:
- Muscle mass: more muscle means a higher healthy weight, because muscle is dense and metabolically valuable.
- Body-fat distribution: where you carry fat (especially around the waist) affects health risk independent of total weight.
- Bone density and frame: a larger skeleton naturally weighs more.
- Age: muscle tends to decline with age, so the same weight can mean more body fat over time.
- Overall health: blood pressure, blood sugar, fitness and family history matter more than hitting an exact number.
How to use the number sensibly
Treat the four-formula average and the BMI range as guardrails, not a finish line. A few practical tips:
- Aim for the range, not a single pound count - any weight inside the healthy-BMI band is a reasonable goal.
- Track trends, not days: weight fluctuates with hydration, sodium and time of day, so look at weekly averages.
- Pair it with composition: a tape-measure waist reading or a body-fat estimate tells you far more than the scale alone.
- Change gradually: about 0.5 to 2 pounds per week is the widely recommended safe pace.
- Strength-train: preserving muscle while losing fat keeps you healthier even if the scale moves slowly.
Limitations and assumptions
This calculator is a quick reference, not a clinical assessment. Keep these limits in mind:
- It uses only height and sex - no muscle, body fat, frame, age or health data.
- The formulas are least reliable at the extremes of height, well below 5 feet and at very tall heights.
- They were not designed for children, pregnancy, or older adults with changing muscle mass.
- The four equations disagree by several pounds, which is why the average and the BMI range are more useful than any single value.
- None of these numbers diagnose anything - a healthy weight for you may sit outside the formula estimate.
How it compares to related calculators
This page answers "what is a reference weight for my height?" If you have a different question, a sister tool fits better:
- To check whether your current weight is in the healthy band, use the BMI Calculator.
- To estimate the share of your body that is fat, use the Body Fat Calculator.
- To see your muscle, bone and water mass, use the Lean Body Mass Calculator.
- To plan a path toward a target weight, use the Weight Loss Calculator.
Sources
- U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) - Weight Management: healthy weight and BMI.
- U.S. National Heart, Lung, and Blood Institute (NHLBI) - BMI and the 18.5–24.9 normal range.
- Devine BJ (1974), Robinson JD et al. (1983), Miller DR et al. (1983), Hamwi GJ (1964) - original ideal body weight equations.
⚠️ Common mistakes & edge cases
Treating one number as a hard target
The formulas give a single figure, but health spans a range. Aiming for an exact "ideal" pound count can be both unrealistic and unnecessary - use the healthy-BMI range as your window instead.
Ignoring muscle mass
Because these equations use only height and sex, a muscular person can appear "overweight" by ideal-weight standards while carrying healthy body fat. Athletes especially should not chase a lower number on this basis.
Using it for children or during pregnancy
These adult formulas do not apply to growing children, teenagers, or pregnant women. Children use age-and-sex growth percentiles, and pregnancy weight goals come from a clinician.
Mixing up units
Entering a height in centimeters while reading pounds (or vice versa) throws the result off badly. Confirm the unit toggle matches your input - the calculator always shows both lb and kg to make this easy to check.
❓ Frequently asked questions
What is ideal body weight (IBW)?
Ideal body weight is a reference figure for what a person of a given height and sex is estimated to weigh. The classic formulas (Devine, Robinson, Miller, Hamwi) were originally developed for medication dosing and insurance height-weight tables, not as personal fitness goals. They give a single number for height; in reality a healthy weight is a range.
Which ideal weight formula is most accurate?
No single formula is definitively 'correct' - they were each derived from different data and give slightly different numbers. The Devine formula is the most widely used in clinical settings and underlies many drug-dosing equations. This calculator shows all four plus their average so you can see the spread rather than relying on one number.
How is ideal weight calculated from height?
Each formula uses a base weight at 5 feet (60 inches) of height and adds a fixed amount for every inch above that. For example, the Devine formula uses 50 kg + 2.3 kg per inch over 5 ft for men, and 45.5 kg + 2.3 kg per inch over 5 ft for women. The calculator converts the result to pounds.
What is the difference between ideal weight and BMI?
Ideal-weight formulas give one number per height. BMI instead defines a healthy weight range (BMI 18.5 to 24.9). The BMI range is generally a more realistic target because it acknowledges that many weights can be healthy for the same height. This tool shows both - the four formula estimates and your BMI-based range.
Does ideal weight account for muscle or frame size?
No. These formulas use only height and sex, so they can read low for very muscular or large-framed people (muscle is dense) and may not fit petite frames well. Athletes in particular often exceed their 'ideal weight' while having healthy body fat. Pair this estimate with a body-fat or lean-body-mass measure for a fuller picture.
Is the ideal weight calculator accurate for everyone?
It is a rough guide, not a diagnosis. The formulas are less reliable at the extremes of height and were not designed for children, pregnant women, older adults with changing muscle mass, or competitive athletes. Use it as a starting point and talk to a doctor or registered dietitian about a goal that fits your body and health.
What is a healthy weight range for my height?
The healthy-BMI range shown here is the span of weights that fall between a BMI of 18.5 and 24.9 for your height. For a 5'6" adult that is roughly 115 to 154 pounds. Where you sit within that range depends on muscle mass, body composition and personal health factors.
Why does my ideal weight differ between men and women?
Each formula uses a lower base weight for women than for men at the same height, reflecting average differences in body composition - men typically carry more lean muscle and bone mass. For example, the Devine base is 50 kg for men versus 45.5 kg for women, with the same 2.3 kg per inch added above 5 feet. That is why a man and a woman of identical height get different ideal-weight numbers.
How do I use the ideal weight calculator?
Pick your sex, choose imperial or metric units, and enter your height. The calculator instantly returns all four formula estimates, their average, and the BMI-based healthy weight range for your height. There is nothing to submit - the numbers update as you type, so you can try different heights or switch units to cross-check the result.
Can I use ideal body weight for medication dosing?
Some clinical drug-dosing equations do use ideal body weight or adjusted body weight, and the Devine formula was created for exactly that purpose. However, dosing decisions belong to a qualified clinician or pharmacist who weighs kidney function, actual weight and the specific drug. Do not use this calculator to set your own medication dose.
Should athletes use this calculator?
Athletes can use it for reference, but the result will often read low because muscle is denser than fat. A lean, muscular athlete may sit above their 'ideal weight' while having an excellent body-fat percentage. For athletes, a body-fat or lean-body-mass measurement is far more meaningful than an ideal-weight number based on height alone.
How can I reach a weight inside my healthy range?
If your current weight is outside the BMI 18.5-24.9 band, gradual change is the safest path: roughly 0.5 to 2 pounds per week through modest calorie adjustments, regular activity and strength training to preserve muscle. Focus on the range rather than a single formula number, and ask a doctor or registered dietitian for a plan tailored to your health and goals.
💡 Good to know
"Ideal weight" was never meant to be a fitness goal
The Devine, Robinson, Miller and Hamwi formulas were built for medication dosing and insurance height-weight tables. They give one number per height, but a healthy weight is a range - use the BMI band as your real target.
A muscular body can beat its "ideal weight"
Muscle is denser than fat, so lean, athletic people often weigh above the formula estimate while carrying healthy body fat. If you train hard, judge yourself by body composition, not by this single number.
The range matters more than the point estimate
The four formulas disagree by several pounds, and the healthy-BMI window can span 30-40 lb for a given height. Anywhere inside that band is a reasonable place to be - there is no need to chase an exact figure.