Ideal Weight Calculator: Your Healthy Weight Range for Your Height

Search for your ideal weight and you get a dozen different answers, each quoted to the decimal. That precision is misleading. The classic formulas were built from insurance tables decades ago and disagree with each other by several kilograms. What the research actually supports is a healthy weight range for your height, with a sensible reference point inside it. This calculator gives you both, plus every classic formula for comparison.

Key takeaways

1. Your healthy weight range is the weight that puts you between a BMI of 18.5 and 24.9 at your height, the WHO classification for adults

2. The Devine, Robinson, Miller and Hamwi formulas each imply a slightly different BMI, which is why they disagree for the same person

3. In large cohorts, mortality is lowest across a whole band of BMI 20 to 25, so any weight in that band is a healthy target, not just one number

Below you will find how each formula works, why a range beats a single number, what changes after 65, and when the scale tells you less than you think.

What Is Ideal Weight?

The term is older than most people assume. Life insurers in the early twentieth century compiled height-weight tables, noticed that certain weights went along with lower mortality, and began calling them "desirable" or "ideal". Clinicians later needed a quick estimate of lean weight for drug dosing, and turned those tables into simple equations. Pai and Paloucek traced this history and concluded that the equations resemble each other because the tables behind them do.

So "ideal weight" never meant the weight at which you are healthiest. It meant a statistical norm from a specific population, later repurposed for pharmacy math. Today two approaches exist side by side: a formula that returns one number, and a BMI-based range. Both use only your height, and neither can see how much of your weight is muscle or fat. Keep that in mind when you read your result.

The Ideal Weight Formulas Compared

All four classic formulas start at a base weight for a height of 5 feet (152.4 cm) and add a fixed amount for every inch above it. The constants below are the ones tabulated in Peterson et al. 2016:

  • Devine (1974): men 50.0 kg + 2.3 kg per inch; women 45.5 kg + 2.3 kg per inch. The version that became standard for drug dosing.
  • Robinson (1983): men 52 kg + 1.9 kg per inch; women 49 kg + 1.7 kg per inch. Derived from Metropolitan Life tables for drug dosage calculations.
  • Miller (1983): men 56.2 kg + 1.41 kg per inch; women 53.1 kg + 1.36 kg per inch. Also built for pharmacy use, with a flatter slope.
  • Hamwi (1964): men 106 lb + 6 lb per inch; women 100 lb + 5 lb per inch, roughly 48.1 kg + 2.7 kg and 45.4 kg + 2.3 kg.
  • Broca: height in cm minus 100, the same for everyone. Simple, but it drifts upward for tall people.

Run them for a man who is 180 cm tall and you get 75.0 kg (Devine), 72.6 kg (Robinson), 71.5 kg (Miller), 77.7 kg (Hamwi) and 80 kg (Broca). That is a spread of more than 8 kg for one body. The reason is simple: each formula quietly targets a different BMI, from about 21 to 24 depending on formula and sex, and most of them overshoot at tall heights and undershoot at short ones. None of them is wrong in its own frame. They just answer slightly different questions.

Why a Healthy Weight Range Beats a Single Number

BMI is weight divided by height squared, so you can turn any BMI into a weight for your height: weight = BMI × height (m)². The WHO classification defines 18.5 to 24.9 as the healthy range for adults. For 180 cm, that is 59.9 to 80.7 kg. If you prefer mental math, Peterson et al. offer a shortcut that stays within about half a percent: weight = 2.2 × BMI + 3.5 × BMI × (height in m minus 1.5).

The strongest argument for a range comes from outcome data. The Global BMI Mortality Collaboration pooled 239 prospective studies with over 10 million participants. Among never-smokers without chronic disease, all-cause mortality was equally low from BMI 20 to 25, and rose both below 20 and throughout the overweight range. There is no single sweet spot, just a broad plateau.

That is why the calculator shows BMI 22 as a reference in the middle of your range rather than as a goal. If your weight sits anywhere between the lower and upper end, chasing a specific number rarely improves your health. How you build and keep that weight matters more.

Ideal Weight After 65

The picture shifts with age. A meta-analysis of 32 studies in adults aged 65 and over used a BMI of 23.0 to 23.9 as the reference. Mortality was 12% higher at a BMI of 21.0 to 21.9 and 19% higher at 20.0 to 20.9. Being overweight was not linked to higher mortality in this age group, and risk only started to rise above a BMI of about 33.

The practical takeaway: after 65, the lower part of the standard range is not a safe target, and unintended weight loss deserves a conversation with your doctor. Enter your age in the calculator and it flags this automatically.

When the Number Misleads: Muscle, Body Fat and Ancestry

BMI and every ideal weight formula share one blind spot: they cannot tell muscle from fat. A meta-analysis covering nearly 32,000 people found that the usual BMI cut-offs for obesity are specific but not sensitive: they miss about half of the people who actually carry excess body fat. The error runs both ways. A strength athlete can sit above the range with little fat, while someone inside the range can still carry too much fat and too little muscle.

Two quick checks close most of that gap. Estimate your body fat with the body fat calculator, and measure where fat sits with the waist-to-hip ratio calculator. Where fat sits matters as much as how much of it there is.

Ancestry matters too. A WHO expert consultation found that many Asian populations face higher risk at lower BMI values and proposed additional public health action points at a BMI of 23 and 27.5. If that applies to you, treat the upper part of the standard range with more caution.

How to Use Your Result

Your result is a starting point for a decision, not a verdict. Here is how to act on it:

  • Above the range: check body fat and waist first. If both confirm excess fat, aim for a moderate pace of loss. The calorie deficit calculator turns your numbers into a daily target, and the protein calculator helps you keep muscle while you lose.
  • Inside the range: stop chasing the scale. Strength training and enough protein improve the composition of the weight you already have.
  • Below the range: focus on gaining muscle, not just weight, and talk to a doctor if the loss was unintended or you are over 65.

Whichever group you are in, trends beat single readings. The huuman app keeps your weight, meals and training in one place, so your huuman Coach can adjust your plan as your body changes. For the rest of your picture, explore all huuman tools.

Frequently Asked Questions

What is the ideal weight for my height?

For adults, the healthy range is the weight that gives you a BMI of 18.5 to 24.9. At 170 cm that is 53.5 to 72.0 kg, with 63.6 kg at the reference BMI of 22. At 180 cm it is 59.9 to 80.7 kg. Enter your height above to get your exact range in kg or lb.

Which ideal weight formula is the most accurate?

None of them measures health directly. They estimate a height-based norm. Among the classic equations, Robinson tracks a constant BMI most closely. The BMI-based equation by Peterson et al. matches any target BMI within about 0.5% and gives you a whole range instead of one number, which is why this calculator leads with the range.

Is ideal weight different for men and women?

In the classic formulas, yes. Devine, for example, gives women 4.5 kg less than men at every height. The BMI range is the same for both sexes, because it describes weight relative to height rather than body composition. That is one more reason to pair it with a body fat estimate.

Does ideal weight change with age?

For most adults, the standard range applies unchanged. From 65, the evidence shifts: mortality is lowest at a somewhat higher BMI, and risk rises below a BMI of about 23. Older adults should avoid aiming for the bottom of the range and should take unintended weight loss seriously.

Can I be healthy above my ideal weight?

Often, yes. Muscular people regularly sit above the range with healthy body fat, and in pooled cohort data the increase in mortality just above BMI 25 is small. What matters is whether the extra weight is fat, and where it sits. Check your body fat and waist-to-hip ratio before deciding you need to lose weight.

Further reading

References

  1. Peterson CM et al. - Universal equation for estimating ideal body weight and body weight at any BMI (2016)
  2. Pai MP & Paloucek FP - The origin of the "ideal" body weight equations (2000)
  3. Robinson JD et al. - Determination of ideal body weight for drug dosage calculations (1983)
  4. Miller DR et al. - Determining ideal body weight (and mass) (1983)
  5. World Health Organization - Obesity: preventing and managing the global epidemic (2000)
  6. Global BMI Mortality Collaboration - Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies (2016)
  7. Winter JE et al. - BMI and all-cause mortality in older adults: a meta-analysis (2014)
  8. WHO Expert Consultation - Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies (2004)
  9. Okorodudu DO et al. - Diagnostic performance of body mass index to identify obesity as defined by body adiposity (2010)

About this article · Written by the huuman Team. Our content is based on peer-reviewed research and clinical guidelines. We follow editorial standards grounded in scientific evidence.

This article is for educational purposes only and does not constitute medical advice. Health and training decisions should be discussed with qualified professionals.