Ideal Weight Calculator: What's a Healthy Weight for Your Height?

How much should you weigh?

It's a question people have been asking for decades, and one that has produced plenty of charts, equations, and online calculators.

Enter your height, sex, and sometimes your age, and you're given a number that's supposedly your ideal body weight.

Simple enough.

Except there's a pretty significant problem with that approach.

Two people can be the same height, weigh exactly the same amount, and have very different body compositions.

One might have substantially more muscle. The other might carry more body fat. Their strength, cardiovascular fitness, metabolic health, and physical performance could also be completely different.

Yet most traditional ideal weight calculators would give them the same result.

That doesn't make these formulas completely useless. They can provide a general reference point.

But I think it's important to understand what they're actually measuring, how they were developed, and why your healthiest weight may be different from the number a calculator produces.

We created our free Ideal Weight Calculator to compare four established ideal body weight formulas, show a BMI-based reference range, and estimate body weight at a selected body fat percentage.

Rather than telling you there's one perfect number, it gives you several ways to put your weight into context.

TLDR

• There is no single ideal body weight that applies to everyone of the same height.
• Traditional ideal body weight equations use height and sex to estimate a reference weight, but they don't directly account for muscle mass, body fat, or physical fitness.
• The Devine, Robinson, Miller, and Hamwi equations can produce different results for the same person.
• BMI provides a population-level weight classification, but it cannot distinguish muscle from fat.
• Body composition, waist circumference, health indicators, and physical performance often provide more useful information than scale weight alone.
• Lean body mass can be used to estimate body weight at a selected body fat percentage, assuming lean mass remains unchanged.
• For athletes, the lowest possible body weight is rarely a useful performance goal.

Want to compare the formulas? Try our free Ideal Weight Calculator to see your estimated weight range and how it compares with your current weight.

What Is Ideal Body Weight?

Ideal body weight, commonly abbreviated IBW, is a calculated weight based on characteristics such as height and sex.

Historically, these calculations have been used for several purposes, including estimating medication dosages and certain clinical nutritional requirements.

That history matters.

Many of the equations now presented online as ways to determine your healthiest or most attractive body weight were not originally developed to answer those questions.

For example, the Devine equation was introduced in a clinical context related to drug dosing.

It wasn't designed to determine the perfect weight for a marathon runner, recreational lifter, or someone trying to improve their metabolic health.

Over time, these equations became popular as general body weight references.

The problem is that a mathematical reference weight and an individual's optimal body weight aren't necessarily the same thing.

How to Calculate Ideal Body Weight

Several equations are commonly used to estimate ideal body weight.

Most start with a reference weight for someone who is five feet tall and then add a certain amount for each additional inch of height.

Our calculator compares four of the better-known equations.

1. Devine Formula

The Devine equation was published in 1974 and remains widely recognized in clinical practice.

For men:

Ideal Body Weight (kg) = 50 + 2.3 × (Height in inches − 60)

For women:

Ideal Body Weight (kg) = 45.5 + 2.3 × (Height in inches − 60)

Let's use a hypothetical male who is 5 feet 10 inches tall.

That's 70 inches.

IBW = 50 + 2.3 × (70 − 60)

IBW = 50 + 23

Estimated ideal body weight = 73 kg, or approximately 161 pounds.

That number is a reference derived from the equation.

It doesn't mean every 5-foot-10 male should weigh 161 pounds.

2. Robinson Formula

The Robinson equation was introduced in 1983 as a modification of earlier ideal body weight calculations.

For men:

IBW (kg) = 52 + 1.9 × (Height in inches − 60)

For women:

IBW (kg) = 49 + 1.9 × (Height in inches − 60)

For the same 5-foot-10 male:

IBW = 52 + 1.9 × 10

IBW = 71 kg

That's approximately 157 pounds.

Already, we have a different estimate.

3. Miller Formula

The Miller equation is another commonly cited modification.

For men:

IBW (kg) = 56.2 + 1.41 × (Height in inches − 60)

For women:

IBW (kg) = 53.1 + 1.36 × (Height in inches − 60)

For our 5-foot-10 male:

IBW = 56.2 + 1.41 × 10

IBW = 70.3 kg

That's approximately 155 pounds.

4. Hamwi Formula

The Hamwi method is a traditional rule-of-thumb approach to estimating ideal body weight.

A commonly used version is:

For men:

IBW (kg) = 48 + 2.7 × (Height in inches − 60)

For women:

IBW (kg) = 45.5 + 2.2 × (Height in inches − 60)

For our example:

IBW = 48 + 2.7 × 10

IBW = 75 kg

That's approximately 165 pounds.

Comparing the Four Ideal Weight Formulas

Let's put those calculations side by side.

For a male who is 5 feet 10 inches tall:

That's a range of approximately 10 pounds.

And remember, we haven't considered body composition, training history, age, or health status.

These formulas simply produce different mathematical estimates.

I wouldn't interpret one as inherently more correct than the others for determining a person's healthiest weight.

A note about height: These traditional equations were generally designed around heights of at least five feet. They shouldn't be extrapolated indiscriminately to shorter individuals.

What Is a Healthy Weight for Your Height?

Another common approach uses body mass index, or BMI.

BMI is calculated using weight and height.

BMI = Weight (kg) ÷ Height (m)²

For adults, commonly used BMI categories are:

These are screening categories, not individual diagnoses.

You can rearrange the BMI equation to estimate the body weight associated with a selected BMI.

Body Weight (kg) = BMI × Height (m)²

For example, a person who is 5 feet 10 inches tall has a height of approximately 1.778 meters.

At a BMI of 18.5:

Weight = 18.5 × 1.778²

That's approximately 129 pounds.

At a BMI of 24.9:

Weight = 24.9 × 1.778²

That's approximately 174 pounds.

So the conventional BMI-based healthy weight range for someone who is 5 feet 10 inches tall is approximately 129–174 pounds.

That's considerably broader than the range produced by the four traditional ideal body weight formulas.

And even that range has limitations.

Healthy Weight Chart by Height

The following table shows approximate weight ranges corresponding to an adult BMI of 18.5–24.9.

These are mathematical ranges derived from BMI, not individualized weight recommendations.

They also shouldn't be applied to children, adolescents, or pregnant individuals in the same way as the standard adult BMI categories.

For a more detailed assessment, you can use our BMI and Waist-to-Height Ratio Calculator.

Why Ideal Weight Calculators Can Be Misleading

Let's compare two hypothetical men.

Both are 5 feet 10 inches tall.

Both weigh 190 pounds.

Both have a BMI of approximately 27.3.

But their body compositions are different.

Person A:

• Body weight: 190 pounds
• Body fat: 12%
• Estimated fat mass: 22.8 pounds
• Estimated fat-free mass: 167.2 pounds

Person B:

• Body weight: 190 pounds
• Body fat: 30%
• Estimated fat mass: 57 pounds
• Estimated fat-free mass: 133 pounds

Their scale weights are identical.

Their BMI values are identical.

Their traditional ideal body weight estimates would also be identical.

Yet there's a difference of more than 34 pounds in estimated fat mass.

This is why I don't think scale weight alone is a particularly useful measure of body composition.

BMI still has value as a population-level screening tool, and higher BMI is associated with certain health risks.

But for individuals, especially those who train regularly, additional measurements can provide important context.

Does Muscle Mass Affect Your Ideal Weight?

Absolutely.

Someone with more muscle mass may weigh considerably more than another person of the same height without having excessive body fat.

This is especially relevant for people who participate in resistance training or sports requiring substantial strength and power.

A muscular individual may fall into the BMI overweight category while having a relatively low body fat percentage.

That doesn't mean BMI is completely useless.

It means BMI should be interpreted alongside other information.

For people who exercise regularly, I would place more emphasis on body composition, waist circumference, physical performance, and relevant health indicators than on whether their weight matches an old prediction equation.

Ideal Weight vs. Lean Body Mass

Lean body mass is the portion of your body weight that isn't classified as fat mass.

It includes skeletal muscle, organs, bones, blood, water, and other non-fat tissues.

If you know your approximate body fat percentage, you can estimate lean body mass using:

Lean Body Mass = Body Weight × (1 − Body Fat Percentage ÷ 100)

For example, suppose you weigh 200 pounds and have 20% body fat.

Lean body mass = 200 × 0.80

Estimated lean body mass = 160 pounds.

This becomes useful when estimating what your body weight might be at a different body fat percentage.

Our Lean Body Mass Calculator can perform these calculations automatically.

How to Calculate Your Goal Weight Using Body Fat Percentage

Instead of choosing a target weight based entirely on height, another approach is to estimate the weight associated with a selected body fat percentage.

The formula is:

Target Body Weight = Lean Body Mass ÷ (1 − Target Body Fat Percentage ÷ 100)

Let's say you're currently 200 pounds at 20% body fat.

Your estimated lean mass is 160 pounds.

Now suppose you want to see what your weight would be at 15% body fat while maintaining the same lean mass.

Target weight = 160 ÷ 0.85

Estimated target weight = 188.2 pounds.

That would represent a weight difference of approximately 11.8 pounds.

But this calculation makes a major assumption.

It assumes your lean body mass remains completely unchanged.

In reality, weight loss often involves changes in fat mass, muscle, glycogen, water, and other tissues.

This is why I would treat the result as a hypothetical scenario rather than a prediction or recommendation.

Also, a particular body fat percentage isn't automatically appropriate for everyone.

Does Your Ideal Weight Change With Age?

This is a common question.

Many online calculators include age as an input, while traditional ideal body weight formulas generally do not.

Your body composition can certainly change with age.

People may lose muscle mass, gain fat mass, or experience changes in fat distribution.

However, there isn't one universally accepted equation that determines your ideal weight simply by adding an age adjustment.

In older adults, maintaining adequate muscle mass and physical function can be especially important.

A weight that appears acceptable on a traditional chart may not tell us whether someone has sufficient muscle or strength.

This is another reason I wouldn't rely exclusively on ideal body weight formulas.

What About Body Frame Size?

Some older ideal weight charts classify individuals as having small, medium, or large body frames.

The idea is that people with larger skeletal structures may naturally weigh more at the same height.

There is some logic to that.

Skeletal dimensions vary among individuals.

But common frame-size classifications are relatively crude, and they don't directly measure muscle mass or body fat.

For most people, evaluating actual body composition is more informative than trying to categorize themselves as small-, medium-, or large-framed.

Is BMI a Good Measure of Health?

BMI can be useful.

It is inexpensive, easy to calculate, and associated with health outcomes at the population level.

But it has limitations.

It doesn't distinguish between fat mass and muscle mass.

It doesn't directly measure where fat is stored.

And it doesn't capture cardiovascular fitness, strength, or other aspects of health.

Fat distribution is particularly relevant.

Greater abdominal fat accumulation is associated with increased cardiometabolic risk, which is one reason waist circumference and waist-to-height ratio can provide useful additional information.

A person with a BMI in the conventional healthy range can still have unfavorable body composition or metabolic risk factors.

Conversely, someone with a BMI above that range may have relatively high muscle mass and favorable health indicators.

The number needs context.

What Is the Best Way to Determine a Healthy Weight?

I wouldn't start by trying to identify one perfect number.

Instead, I would look at several measurements together.

Body Composition

An estimate of body fat percentage and lean mass can help distinguish changes in fat from changes in non-fat tissue.

Waist Circumference

Waist measurements can provide additional information about abdominal fat distribution.

Physical Performance

Strength, endurance, mobility, and the ability to train and recover are useful indicators of physical function.

Health Markers

Blood pressure, blood lipids, glucose regulation, and other clinical measurements provide information that a weight chart cannot.

Weight Trends

Changes in body weight over time can be informative, particularly when interpreted alongside changes in waist circumference and physical performance.

For someone trying to improve body composition, I would rather see a combination of improved strength, reduced waist circumference, and sustainable training than an arbitrary number on the scale.

Ideal Weight for Runners and Endurance Athletes

Endurance athletes are a particularly good example of why ideal weight formulas have limitations.

In sports such as distance running, body mass can influence the energy cost of movement.

But lower body weight doesn't automatically produce better performance.

Losing weight can reduce the energy required to move the body.

However, excessive energy restriction can also impair training quality, recovery, muscle function, and health.

Athletes who consistently consume insufficient energy relative to their training demands may develop low energy availability.

Prolonged low energy availability can contribute to Relative Energy Deficiency in Sport (REDs), which can affect bone health, hormonal function, recovery, and performance.

I would be especially cautious about using an ideal weight calculator to establish a target weight for a marathon or ultramarathon.

The better question is whether your current body composition and fueling strategy support your training and performance goals.

Should You Lose Weight If You're Above Your Ideal Weight?

Not automatically.

If a calculator estimates your ideal weight at 160 pounds and you currently weigh 185, that doesn't mean you need to lose 25 pounds.

First, consider why your weight differs from the estimate.

Do you have substantial muscle mass?

What is your approximate body fat percentage?

What does your waist circumference look like?

How are your health markers?

How do you feel and perform?

If reducing body fat would benefit your health or performance, weight loss may be appropriate.

But the decision should be based on more than a comparison with a mathematical reference weight.

And if you do decide to lose weight, the rate and magnitude of weight loss matter.

An unnecessarily aggressive calorie deficit can make it more difficult to maintain muscle, recover from training, and sustain progress.

Our Calorie Deficit Calculator can help estimate a starting point for managing calorie intake.

Common Mistakes When Using an Ideal Weight Calculator

Treating the Result as a Medical Diagnosis

Traditional ideal body weight equations were not designed to diagnose health status.

Ignoring Body Composition

Two people with the same height and weight may have very different amounts of muscle and body fat.

Assuming Lower Weight Is Always Better

Reducing body weight isn't necessarily beneficial if it compromises strength, recovery, health, or athletic performance.

Comparing Yourself to Someone Else

Height alone doesn't determine an appropriate body weight.

Choosing an Extremely Low Body Fat Target

A mathematical formula can estimate body weight at a selected body fat percentage, but it cannot determine whether that percentage is healthy or sustainable.

Focusing Only on the Scale

Changes in strength, waist circumference, fitness, and other indicators can provide useful information that scale weight misses.

Use Our Free Ideal Weight Calculator

We created our free Ideal Weight Calculator to give you more context than a single number.

Enter your height, current weight, and the sex used for the prediction equations.

The calculator will show:

• Your Devine ideal body weight estimate
• Your Robinson estimate
• Your Miller estimate
• Your Hamwi estimate
• The range across all four equations
• A BMI-based reference weight range
• Your current BMI
• A comparison of your current weight with the traditional formulas

If you know your approximate body fat percentage, you can also estimate what your weight would be at a selected body fat percentage while maintaining lean mass.

It's a useful way to explore different weight estimates.

Just don't confuse those estimates with a definitive answer about what you should weigh.

Frequently Asked Questions

What is the ideal weight for my height?

There is no single ideal weight for everyone of the same height. Traditional equations and BMI ranges provide reference estimates, but appropriate body weight also depends on body composition, health, and individual circumstances.

How do I calculate my ideal body weight?

Common methods include the Devine, Robinson, Miller, and Hamwi equations. These use height and sex to estimate a reference body weight. Our free calculator compares all four.

Is ideal body weight the same as healthy weight?

Not necessarily. Ideal body weight equations produce mathematical reference values, while health depends on multiple factors beyond body weight.

Does age affect ideal body weight?

Age can influence body composition and health considerations, but most traditional ideal body weight equations do not include age.

Is BMI an accurate way to determine ideal weight?

BMI is a useful screening tool, particularly at the population level, but it cannot distinguish fat from muscle or directly assess individual health.

Can muscle make you weigh more than your ideal weight?

Yes. People with greater muscle mass may weigh more than traditional ideal body weight estimates without necessarily having excessive body fat.

What is a healthy BMI?

For most nonpregnant adults, the conventional healthy BMI category is 18.5–24.9. However, BMI should be interpreted alongside other health and body composition measurements.

How do I calculate my goal weight from body fat percentage?

Estimate your lean body mass, then divide it by one minus your selected target body fat percentage expressed as a decimal. This assumes lean mass remains unchanged.

Should athletes use ideal weight calculators?

Athletes can use them as general reference tools, but the results should not be treated as performance targets. Body composition, adequate fueling, recovery, and performance are more important considerations.

Is being below your calculated ideal weight unhealthy?

Not necessarily. A formula-based estimate alone cannot determine whether someone's weight is healthy. Additional context is needed.

References

1. Devine BJ. Gentamicin therapy. Drug Intelligence & Clinical Pharmacy. 1974;8:650–655.
2. Robinson JD, Lupkiewicz SM, Palenik L, Lopez LM, Ariet M. Determination of ideal body weight for drug dosage calculations. American Journal of Hospital Pharmacy. 1983;40(6):1016–1019.
3. Miller DR, Carlson JD, Hanson J, et al. Determining ideal body weight. American Journal of Hospital Pharmacy. 1983;40(10):1622.
4. Nuttall FQ. Body mass index: obesity, BMI, and health: a critical review. Nutrition Today. 2015;50(3):117–128. https://doi.org/10.1097/NT.0000000000000092
5. Ross R, Neeland IJ, Yamashita S, et al. Waist circumference as a vital sign in clinical practice: a consensus statement from the IAS and ICCR Working Group on Visceral Obesity. Nature Reviews Endocrinology. 2020;16:177–189. https://doi.org/10.1038/s41574-019-0310-7
6. Heymsfield SB, Wang Z, Baumgartner RN, Ross R. Human body composition: advances in models and methods. Annual Review of Nutrition. 1997;17:527–558. https://doi.org/10.1146/annurev.nutr.17.1.527
7. Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). British Journal of Sports Medicine. 2023;57:1073–1097. https://doi.org/10.1136/bjsports-2023-106994

About the Author

Matt Mosman, MS, CISSN, CSCS, is the Founder and Chief Science Officer of Simply Good Supplements. With a background in exercise science, sports nutrition, and strength and conditioning, Matt focuses on translating scientific research into practical strategies for improving health, fitness, and athletic performance.