Ideal Weight Calculator

Figuring out what you should weigh is surprisingly complicated. You've probably typed your height into some online tool and gotten a number that felt either completely off or oddly reassuring. The truth is, "ideal weight" means different things depending on who you ask and which formula they use. This calculator pulls together the most widely used medical formulas to give you a realistic range, not just one target number. Whether you're setting a fitness goal, tracking progress, or just curious, the results are grounded in the same methods clinicians have relied on for decades.

Enter Details

Age(age 18 to 120 only)

Gender

MaleFemale

Devine (1974) — adults.

Units

Height

Result

Height and sex drive this classic estimate.

Note — This result is an estimate. Talk to a healthcare provider for personalized guidance.

What Is Ideal Body Weight (IBW)?

Ideal body weight is a clinical estimate of how much a person should weigh, based mainly on height and sex. It's been used in medicine for a long time, mostly to calculate drug dosages, assess nutritional needs, and screen for weight-related health risks.

The concept dates back to the mid-20th century, when physicians needed a quick, standardized way to estimate a "reference" weight for patients. It was never really meant to be a cosmetic standard or a personal goal for everyone. Over time, though, it found its way into fitness culture, diet programs, and public health guidelines.

Worth knowing: IBW is a rough estimate, not a precise biological target. Two people with the exact same height can have very different healthy weights depending on body composition, bone density, age, and activity level. The number is a starting point, not a verdict.

Ideal Weight vs. Healthy Weight - What’s the Difference?

These two terms get used interchangeably a lot, but they're not quite the same thing.

Ideal body weight is a formula-derived number, calculated from your height and sex. It's specific and mathematical, but it doesn't account for much beyond those two inputs.

Healthy weight is a broader concept. It's typically defined as a weight range associated with lower risk of chronic disease, better energy, and sustainable physical function. It factors in things like age, muscle mass, cardiovascular health, and even mental well-being.

Someone can fall outside the IBW range and still be perfectly healthy. A highly muscular athlete might weigh significantly more than their "ideal" number suggests. An older adult with low muscle mass might hit the IBW target but still have metabolic concerns. Healthy weight is less about a specific number and more about a range that works for your body over time.

How to Use This Ideal Weight Calculator

Using the calculator is pretty simple. Enter your height, weight, and biological sex, then hit calculate. It runs your inputs through multiple established formulas and returns a range of ideal weight estimates, plus where your current weight sits relative to those targets.

A few things worth keeping in mind before you start:

Use your bare height, measured without shoes, for the most accurate result.
Biological sex matters here because the formulas were built with sex-based differences in lean body mass in mind. Use the sex assigned at birth or whichever most closely reflects your body composition.
Your current weight is optional for some calculations, but including it lets the tool show how far you are from the estimated ideal range.

You'll get a range rather than a single number because different formulas produce slightly different results. That range gives you a more realistic picture than any one formula alone could.

Understanding Your Results

Once the calculator runs, you'll see estimates from several formulas alongside a suggested weight range. Here's how to read them without overthinking it.

If your current weight falls within or close to that range, you're likely in a healthy zone for your height. Well above it? That may be worth bringing up with a doctor, especially if other risk factors are present. Below it is also worth paying attention to. Being underweight carries its own set of health risks that don't always get enough attention.

Honestly, the most useful thing these results can do is start a conversation, either with yourself about your goals, or with a healthcare provider about your overall health picture. Don't treat any single number here as a pass or fail. Bodies are more complicated than that.

How Much Should I Weigh? (By Height & Gender)

General weight ranges by height give a useful ballpark, even if they can't account for every individual variable. The ranges below are based on common IBW formulas and broadly align with what most clinical guidelines consider a healthy weight for adults.

Keep in mind these figures apply to adults with average body frames. Very muscular individuals or those with larger bone structures may naturally sit toward the upper end, or slightly above, without any real health concern.

Ideal Weight for Women by Height (Chart)

Height	Ideal Weight Range (lbs)	Ideal Weight Range (kg)
4'10" (147 cm)	91 – 115 lbs	41 – 52 kg
4'11" (150 cm)	94 – 119 lbs	43 – 54 kg
5'0" (152 cm)	97 – 123 lbs	44 – 56 kg
5'1" (155 cm)	100 – 127 lbs	45 – 58 kg
5'2" (157 cm)	104 – 131 lbs	47 – 59 kg
5'3" (160 cm)	107 – 135 lbs	49 – 61 kg
5'4" (163 cm)	110 – 140 lbs	50 – 64 kg
5'5" (165 cm)	113 – 144 lbs	51 – 65 kg
5'6" (168 cm)	117 – 148 lbs	53 – 67 kg
5'7" (170 cm)	120 – 153 lbs	54 – 69 kg
5'8" (173 cm)	123 – 157 lbs	56 – 71 kg
5'9" (175 cm)	127 – 162 lbs	58 – 74 kg
5'10" (178 cm)	130 – 166 lbs	59 – 75 kg
5'11" (180 cm)	134 – 171 lbs	61 – 78 kg
6'0" (183 cm)	137 – 175 lbs	62 – 79 kg

These ranges reflect averages across multiple formulas. Individual healthy weight can vary based on muscle mass, bone density, and other factors.

Ideal Weight for Men by Height (Chart)

Height	Ideal Weight Range (lbs)	Ideal Weight Range (kg)
5'0" (152 cm)	106 – 130 lbs	48 – 59 kg
5'1" (155 cm)	110 – 135 lbs	50 – 61 kg
5'2" (157 cm)	114 – 140 lbs	52 – 64 kg
5'3" (160 cm)	118 – 144 lbs	54 – 65 kg
5'4" (163 cm)	122 – 149 lbs	55 – 68 kg
5'5" (165 cm)	126 – 154 lbs	57 – 70 kg
5'6" (168 cm)	130 – 159 lbs	59 – 72 kg
5'7" (170 cm)	134 – 164 lbs	61 – 74 kg
5'8" (173 cm)	139 – 169 lbs	63 – 77 kg
5'9" (175 cm)	143 – 174 lbs	65 – 79 kg
5'10" (178 cm)	147 – 179 lbs	67 – 81 kg
5'11" (180 cm)	152 – 185 lbs	69 – 84 kg
6'0" (183 cm)	156 – 190 lbs	71 – 86 kg
6'1" (185 cm)	161 – 196 lbs	73 – 89 kg
6'2" (188 cm)	165 – 201 lbs	75 – 91 kg
6'3" (191 cm)	170 – 207 lbs	77 – 94 kg

Men generally carry more lean muscle mass than women at the same height, which is why these ranges run higher. Same caveat as the women's chart: these are estimates, not absolute targets.

Ideal Weight Formulas Explained

Several formulas have been developed over the years to estimate ideal body weight. They all use height and sex as inputs, but the math differs, which is why they don't always agree. Below are the three you'll most commonly encounter in clinical and fitness settings.

Devine Formula (1974)

The Devine formula is probably the most widely used IBW formula in medicine. Dr. B.J. Devine originally developed it to estimate appropriate drug doses, not as a fitness target. It became the default in clinical settings largely because it was simple and already embedded in medical practice.

Here's how it works:

Men: IBW (kg) = 50 + 2.3 × (height in inches above 5 feet)
Women: IBW (kg) = 45.5 + 2.3 × (height in inches above 5 feet)

For a 5'8" man, that's 50 + 2.3 × 8 = 68.4 kg, or about 151 lbs. Clean, fast, easy to calculate in your head. The downside is that it was developed with limited data and doesn't account for body composition at all. Still a solid baseline reference, though.

Robinson Formula (1983)

The Robinson formula came out of a 1983 paper that tried to refine Devine's work using a larger dataset. The structure is similar, but the base weights and per-inch increments differ slightly.

Men: IBW (kg) = 52 + 1.9 × (height in inches above 5 feet)
Women: IBW (kg) = 49 + 1.7 × (height in inches above 5 feet)

At shorter heights, Robinson tends to produce slightly higher estimates than Devine. At taller heights, Devine often comes out on top. For most people in the average height range, the two formulas land within a few pounds of each other. Robinson is considered a modest refinement, though neither formula has been updated to reflect modern population data.

Peterson Formula - BMI-Based Approach

The Peterson formula takes a different approach entirely. Instead of starting from a fixed base weight and adding per-inch increments, it anchors ideal weight to a specific BMI target.

Men: IBW (kg) = 2.2 × BMI + 3.5 × BMI × (height in meters minus 1.5)
Women: Same formula, but typically solved using a target BMI of 21.5 rather than 22

Because it's BMI-based, the Peterson formula scales more naturally with height and can produce a range of results depending on which target BMI you plug in. It tends to give higher estimates for taller individuals compared to Devine and Robinson, which some researchers argue is more physiologically accurate. It's not as common in day-to-day clinical practice, but it's gaining ground in research.

Which Ideal Weight Formula Is Most Accurate?

Honestly? None of them is definitively the best. Each was developed from a different dataset and for a different original purpose. None was designed to account for modern variation in body composition, ethnicity, or fitness level.

A 2016 review published in Nutrition in Clinical Practice found that all common IBW formulas have notable limitations, especially at height extremes. Very short or very tall individuals tend to get the worst estimates. The Devine formula tends to underestimate ideal weight for tall people and overestimate it for short people. The Peterson formula handles height scaling better, but it's more complex to calculate.

For practical purposes, using the range produced by all three formulas together is smarter than picking just one. If you land in the overlapping zone across all three, that's a reasonably solid target range. If the formulas diverge significantly for your height, that's a signal that the whole concept of a single "ideal" number may not apply well to your body.

Ideal Weight vs. BMI - How Are They Related?

BMI (body mass index) and ideal body weight are related but distinct. BMI is calculated from your actual height and weight and gives you a category: underweight, normal, overweight, or obese. IBW is a target, a weight calculated from height and sex that you're notionally supposed to be aiming for.

In practice, most IBW formulas produce results that correspond to a BMI somewhere between 20 and 25, which falls in the "normal" range. So they're pointing at the same general zone, just from different directions.

The main issue is how they handle body composition. Neither BMI nor IBW can tell the difference between fat and muscle. A 200-pound person with 10% body fat and a 200-pound person with 35% body fat will get the same BMI and the same IBW result, even though their health profiles look completely different.

BMI is easier to calculate from existing measurements and shows up more often in population-level research. IBW is more useful when you're working backward from a goal weight. Both share the same core limitation: they use weight as a proxy for health, and weight alone is a pretty blunt instrument.

Factors That Affect Your Ideal Weight

Height and sex only tell part of the story. A lot of other variables shape what a healthy weight actually looks like for a specific person. Some are biological, some are lifestyle-related, and a few are things most people don't really think about.

Age plays a meaningful role. As people get older, lean muscle mass tends to decline and body fat distribution shifts. Someone at 55 may be healthy at a slightly different weight than they were at 25, even at the same height. Metabolic rate, hormonal changes, and bone density all shift over time.

Ethnicity and genetics matter too. Research has shown that different ethnic groups can have different relationships between weight, body fat percentage, and disease risk at the same BMI. Some health organizations have started adjusting BMI cutoffs for certain populations, and the same logic applies to IBW targets.

Muscle Mass vs. Body Fat

This is probably the biggest reason IBW numbers can mislead people. Muscle is denser than fat, so a muscular person weighs more at the same size as someone carrying higher body fat. Two people can look and feel completely different and still hit the same number on the scale.

Someone who lifts regularly and carries a lot of lean muscle may weigh 15 or 20 pounds above their IBW estimate and still have an excellent metabolic health profile. Meanwhile, someone at or below their IBW but with very little muscle and relatively high body fat, sometimes called "skinny fat" or normal-weight obesity, can have elevated health risks despite hitting the target number.

Body fat percentage is a much better indicator of body composition than weight alone. For most healthy adults, somewhere between 10 and 20% for men and 18 to 28% for women is generally considered a healthy range, though it varies by age and fitness level. If you have access to a reliable body composition measurement, it's worth using alongside any weight-based estimate.

Body Frame Size and Weight Differences

Not everyone is built the same, and bone structure is part of that. People are generally classified as small, medium, or large frame based on wrist circumference or elbow breadth, and frame size can account for a 10 to 15% difference in healthy weight at the same height.

A simple way to estimate your frame: wrap your thumb and middle finger around your wrist. If they overlap, you likely have a small frame. If they just touch, medium. A gap means large frame.

Larger-framed individuals naturally carry more bone mass and often more muscle, so they'll typically land at the higher end of any weight range without it being a concern. Smaller-framed people will generally be healthier toward the lower end. Most standard IBW formulas don't adjust for frame size at all, which is one reason they produce a range rather than one specific number.

Limitations of Ideal Body Weight Calculators

These calculators are useful, but they have real limits worth understanding before you put too much stock in the result.

The formulas themselves are old. Devine's is from 1974. Robinson's from 1983. Both were built on relatively small datasets that didn't represent the full diversity of the modern population. A lot has changed about how we understand body composition, metabolic health, and the relationship between weight and disease risk since then.

They also can't account for what's actually going on inside your body. Two people with identical height, sex, and weight can be in very different states of health depending on where their fat is distributed, how much muscle they carry, and what's happening with their blood pressure, blood sugar, and cholesterol.

IBW calculators also tend to struggle at the extremes. For people under 5 feet tall or over 6'2", the linear formulas often produce estimates that don't hold up physiologically. The same goes for older adults, pregnant women, and highly trained athletes.

Use this calculator as one data point among several. Pair it with a conversation with your doctor, a body composition analysis if you can get one, and an honest sense of how you feel and how your body is actually functioning. The number is a starting point, not the finish line.