How Much Should You Weigh Based on Your Height and Age?

If you're wondering how much you should weigh, there's no simple answer. A person's weight is influenced by a variety of factors, including your genes, how you eat, your activity level and the environment where you live. Some of these things are under your control, while others are not.

You'll sometimes hear about an "ideal" weight by height, but there's really no such thing. That's a notion that originated with insurance companies, says Mir Ali, MD, bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California.

"When patients developed certain conditions, they'd record their height and weight. It came out like a bell-shaped curve, so most people were in the middle," Dr. Ali says. This, he says, was a poor strategy that led to unrealistic weight expectations.

Still, it's important to aim for a healthy weight — weighing too little or too much is linked with increased risk of many serious health conditions. To that end, it's helpful to know what weight range is reasonable for you, considering your height, frame, background, age and other factors that make you who you are.

Many techniques are available to calculate whether your weight falls in a healthy zone. Each one offers potentially useful insights, but each also has its flaws.

Take a look at some of the options available for determining if your weight is considered healthy or not, along with details about why weight can be an important consideration when it comes to your overall health.

It's not perfect, but you can use this weight and height chart based on body mass index (BMI) from the National Heart, Blood and Lung Institute (NHBLI) to find the intersection of your height and weight and get a general idea of how much you should weigh. (Read more on how to determine and use BMI below.)

Although people are often curious about whether their weight is in the healthy range for their age, the truth is that there's no good answer to that question. There is no true "healthy" or "normal" weight for a particular age because weight is determined by so many other factors.

That said, weight can change with age. After age 30, body fat increases, and then for people AMAB, weight gain tends to continue until age 55, while for people AFAB, it continues until around age 65, according to Mount Sinai. At this point, the age-related weight gain tends to stop, and people go on to lose weight, per Mount Sinai.

While there's no "normal" weight to target, there are weight averages by age that you can use as a very general guideline. But keep in mind that comparing your weight to these numbers (provided by the Centers for Disease Control and Prevention and National Center for Health Statistics) will not give you the best indication of your overall health.

The easiest way to answer your "how much should I weigh?" question is to know your BMI. While BMI doesn't tell the entire story, it's one of the most well-known metrics to assess weight.

"It's a simple calculation. You put in your height and weight and you get a BMI number," Dr. Ali says.

BMI offers a sense of your total body fat, which is more revealing than the number on the scale. With higher amounts of body fat, a person's risk of certain diseases — such as heart disease, high blood pressure and type 2 diabetes — increases, according to Winchester Hospital.

"There are a lot of good studies that show that if a person maintains their weight in that BMI range, then they're less likely to develop health problems because of their weight, and more likely to achieve the typical normal lifespan for this country," Dr. Ali says.

Calculate your BMI using this formula provided by the U.S. National Library of Medicine (NLM):

1. Take your weight (in pounds) and multiply it by 703.
2. Divide that answer by your height (in inches).
3. Divide that result by your height in inches once again.

There are plenty of online calculators available to spare you from doing this math, such as LIVESTRONG.com's BMI Calculator. The Centers for Disease Control and Prevention (CDC) offers a calculator that does not ask for your age or sex. You can also use a chart (see below) to determine your BMI.

Once you have your BMI, you can see which category it falls into. The categories, according to the NLM, include the following:

Doctors and other health experts have been relying on BMI since 1972, according to a June 2014 paper in the ‌International Journal of Epidemiology‌, when it replaced the insurance charts mentioned earlier. (The scientist who established BMI based it on work done by a Belgian mathematician in the 1800s.)

There are a few big advantages to assessing weight with BMI:

1. ‌It's easy and cheap.‌ Many free online calculators and charts are available to do the math for you.
2. ‌BMI helps predict a person's risk of disease.‌ Compared to other methods (more on those later), BMI is an easy, accessible way to get a sense of a person's total body fat. As noted, that's important because there is a strong link between high body fat and obesity-related diseases. That's why BMI can be useful for predicting disease risk, per the Harvard T.H. Chan School of Public Health.
3. ‌Many health organizations use BMI.‌ It's "accepted by essentially all major national and international health organizations," according to a July-August 2016 feature in ‌ACSM's Health & Fitness Journal‌. That means doctors rely on it, and the metric is incredibly common in health-related studies.

The metric is not without its flaws:

1. ‌It may overestimate body fat for athletes or muscular people.‌ "The problem with BMI is it doesn't really take into account body composition," Dr. Ali says. Because muscle weighs more than fat, athletes or other muscular folks may fall into the overweight or obesity categories of the BMI chart, according to the American Council on Exercise (ACE).
2. ‌BMI underestimates body fat for older adults.‌ BMI is also known to be inaccurate for older adults, according to the NHLBI. With age, a person's body composition shifts — to a higher weight with less muscle mass. If an older and younger person both have the same BMI, the older person (on average) will have more body fat, per the CDC.
3. ‌BMI doesn't take into account ethnic backgrounds.‌ Part of the strength of BMI is that only two metrics — height and weight — are required. But treating everyone the same, regardless of ancestry, is a weakness, too. People of Asian descent, for instance, may have a low BMI, but high body fat percentage, per the Mayo Clinic. That means for this population, the tool isn't accurately predicting risk. (The World Health Organization recommends different BMI cutoffs for people of Asian descent.) There are differences in other populations, too — compare a Black and white person with the same BMI, and the Black person will tend to have less body fat, according to the CDC.
4. ‌BMI also doesn't take a person's sex into account.‌ The classic BMI calculator will only look at two calculations: weight and height. But sex matters when it comes to BMI, because people AFAB tend to have more body fat than people AMAB, even if their BMI is the same, per the CDC. To adjust for this problem, some calculators — including LIVESTRONG.com's — also ask people to plug in their age and sex.
5. ‌If you're self-reporting, you can make errors.‌ If your height and weight are taken at the doctor's office, you can probably count on accurate measurements. At home, though, many of us will round up our height while underreporting weight, according to an August 2013 review in ‌Current Research in Nutrition and Food Science‌.
6. ‌BMI can give a false sense of good health.‌ In medical terms, some people are classified as having metabolic obesity, normal weight (MONW) — or, more casually (and controversially), "skinny fat." Basically, this means that a person's BMI indicates a healthy weight, but their percentage of body fat is high — which is linked to all the same increases in health risks as obesity, per the Mayo Clinic.

Sometimes medical professionals will encourage people to measure their waist, either as a solo way of assessing whether their weight is healthy or in conjunction with calculating their BMI.

That's because when it comes to fat, location matters. Measuring your waist helps reveal your amount of belly fat — this consists of both subcutaneous fat, which is soft and lies below the skin, and the visceral fat that's found between your internal organs, according to the Mayo Clinic.

Of these two types of fat, it's visceral fat that's more concerning: Having it is linked to an increased risk of heart disease, type 2 diabetes and high blood pressure, along with other health problems, per the Mayo Clinic.

Follow these steps to measure the circumference of your waist, according to Harvard Health Publishing:

1. Take off your shoes. Remove your top, or wear one that reveals your belly.
2. Stand with your feet together.
3. After an exhale, measure your waist across the navel. Use a soft, fabric measuring tape (not a retractable metal measuring tool), and wrap it around your waist, parallel to the ground.

The number on the measuring tape is your waist circumference.

Harvard Health Publishing groups people's waist sizes into the following risk levels for chronic conditions such as heart disease and type 2 diabetes:

According to the CDC, the average person in the U.S. has a waist circumference that puts them in the "high risk" category:

Some of the benefits of using this method are:

1. ‌It's cheap and simple.‌ As with BMI, few tools are required for the task. So long as you have a flexible tape measure, you can take this measurement.
2. ‌Waist circumference is a good way to predict key health risks.‌ Your risk for developing heart disease and type 2 diabetes increases if fat sits at your waist instead of hips, per the NHLBI.

Some of the flaws of this metric include:

1. ‌It's easy to get it wrong.‌ Determining where precisely to measure (at your bellybutton? Just above?) and ensuring the tape measure isn't tangled can be surprisingly challenging, particularly if you're doing the measurement yourself. Compared to BMI, this method is more likely to be inaccurate, per Harvard Health Publishing.
2. ‌It's not accessible for everyone.‌ For people with a very large waist or mobility issues, taking this measurement may be more challenging, and it may not be as accurate, according to the Harvard T.H. Chan School of Public Health.

While BMI compares a person's weight to their height to get a sense of body fat, the waist-to-hip ratio (WHR) compares a person's waist size to their hip size, with the goal of determining how much fat is stored in this key area.

WHR offers a gauge for your health, Dr. Ali says. "It doesn't really tell you what weight you should be at," he notes. But your WHR can bring context to your weight, giving you a clearer picture of your overall health and letting you know if you're carrying too much belly fat, which, as noted earlier, is linked to serious health risks.

A bigger WHR measure means a person is at higher risk — that is, it's healthier for a person's waist to be smaller than their hips.

Here's how to do it, according to Dr. Ali:

1. Measure your waist circumference using a soft, fabric measuring tape across your bellybutton after an exhale.
2. Measure your hip circumference at their widest point.
3. Divide the waist measurement by the hip measurement.

For example, a person with a 35-inch waist and 45-inch hips would have a 0.78 waist-to-hip ratio.

"If your waist is much larger than your hips, then you're at a higher risk for cardiovascular disease or diabetes," Dr. Ali says, noting that people AMAB tend to carry weight around the belly, while those AFAB usually carry more weight in their hips.

There are a few benefits to assessing whether you're at a healthy weight based on your WHR:

1. ‌WHR is simple and cheap.‌ This is an easy calculation — it only requires two measurements and some division.
2. ‌It's a good predictor of disease‌, according to the Harvard T.H. Chan School of Public Health. In fact, it may be a better predictive tool than BMI: A waist-to-hip ratio was a better predictor for heart attacks than BMI, particularly for people AFAB, according to a January 2018 study in the ‌Journal of the American Heart Association‌. And it's also a preferable predictor for prostate cancer, compared to BMI, according to a March 2017 study in ‌Scientific Reports‌, which looked at more than 1,000 Chinese people who had prostate biopsies.

There are some limitations to this method, such as:

1. ‌It's easy to make mistakes with measurements.‌ Measuring your own body can lead to errors. In this case, two measurements need to be taken, so the opportunity to mess up here is doubled. Because studies point to the waist-to-hip ratio and waist circumference being equally effective at predicting disease risk, it may be preferable to stick to measuring just the waist, per the Harvard T.H. Chan School of Public Health.
2. ‌There may be differences across ethnicities that aren't reflected.‌ Per the WHO, cutoffs for WHR are often determined through studies of people with European ancestry, but it's possible that in people from different ethnicities, thresholds at a different point might be more effective at predicting health outcomes.

As you can likely gather from its name, the waist-to-height ratio (WtHR) looks at the relationship between a person's waist size and height. The goal: "Keep your waist to less than half your height," per a November 2014 opinion piece in ‌BMC Medicine‌.

Again, this can't tell you whether your weight is average or "ideal," but it can serve as a way to put your weight and BMI into context. If you have a high BMI because you're very muscular, for example, your WtHR could potentially indicate whether you're at a healthy weight for your body composition.

1. Measure your waist size (in inches) using a soft, fabric measuring tape across your bellybutton after an exhale.
2. Measure your height (in inches).
3. Divide your height by your waist size.

For example, a person who is 5'4" (aka 64 inches) with a waist circumference of 30 inches would have a WtHR of 2.1 (64/30 = 2.1), which is considered healthy. If that same person had a waist circumference of 38.7, as the average person AFAB does, their WtHR would be 1.65, which is considered unhealthy.

Some of the benefits of using WtHR are:

1. ‌It reveals risk for serious diseases.‌ WtHR "may be a simpler and more predictive indicator" than BMI or waist circumference, per a March 2016 study in ‌BMJ Open‌ that looked at four years' worth of data from the UK National Diet and Nutrition Survey. A February 2017 study in ‌Nature‌ that looked at more than 25,000 middle-aged Chinese people who identified as men found that WtHR was better correlated to heart health than waist circumference.
2. ‌It's easy and cheap.‌ Taking these two measurements and performing the calculation is a relatively simple task, and only requires a tape measure. Plus, no charts are required to know what the ratio indicates.
3. ‌WtHR works for all ethnic groups.‌ For non-white people, BMI isn't always an effective method. In contrast, WtHR (and the philosophy of keeping waist size less than half of height) is "suitable for all ethnic groups," according to the ‌BMC Medicine‌ opinion piece.

The drawbacks of this method mirror those of other methods that require measurements of waist and height: Where you measure matters. If you measure the wrong spot on your waist, it could make the end ratio inaccurate.

Health care providers are eager to know a person's body fat percentage because it's closely linked with many serious (and often chronic) illnesses. The measures above serve as a stand-in for body fat; that is, a high BMI typically (but not always) indicates a high body fat percentage.

Here are a few of the common ways to measure body fat directly, according to the University of Michigan Health:

• ‌Skinfold thickness:‌ After pinching the skin, calipers (think: clamps) are used to measure the skinfold thickness (SFT) in several key areas, including the thigh, back of the arm and waist. Different areas are measured depending on a person's sex. This method is fairly accurate, according to the American Council on Exercise (ACE). The accuracy likely decreases if you attempt to measure on yourself, rather than having a professional use the calipers.
• ‌Underwater weighing:‌ After being weighed normally, a person is then lowered into water and weighed there. The difference between these two measurements reveals body density, per the University of Michigan Health. Another version of this — ‌air displacement plethysmography‌ — compares the air pressure of a sealed chamber when you're in it to when you're not to identify body density, according to the University of Michigan Health.
• ‌DXA:‌ Dual-energy x-ray absorptiometry — a special type of X-ray — reveals the amount and location of fat tissue.

In general, measuring body fat requires a professional — either to take the measurements or to supply the tools and technology. While there are commercially available body fat analyzers, such as body fat scales, these tools are easily affected by several factors, including how hydrated you are, according to the Mayo Clinic.

To get a general idea of your body fat percentage, plug your measurements into LIVESTRONG.com's Body Fat Calculator.

Once you've assessed your body fat, you'll want to know what your number means. The Cleveland Clinic recommends following guidelines laid out in September 2000 in ‌The American Journal of Clinical Nutrition‌ (although keep in mind that there isn't total agreement in the health community about these numbers):

As a more general guideline, the ACE offers the following percentages for everyone, regardless of age:

1. ‌It has a strong link to increased risk of serious diseases.‌ Most of the other measures medical professionals use — like the ones detailed on this list, including BMI, WTH, waist circumference and WtHR — are aimed at trying to get a sense of a person's body fat. For instance, one observational study of more than 50,000 older adults in Canada measured both their BMI and body fat percentage. A low BMI and high body fat percentage were associated with increased mortality, per the April 2016 research in ‌Annals of Internal Medicine‌. This reveals the limitations of BMI — a person with a small frame can still be unhealthy, and BMI isn't always the most accurate of measurements.
2. ‌It's a more helpful measure than BMI when it comes to diabetes.‌ Having abnormal blood sugar (an indicator of diabetes or prediabetes) is more common in people with a normal BMI and high body fat percentage than among those who have overweight with a low body fat percentage, according to an April 2018 study in ‌BMJ Open‌ that drew on information from adults over age 40 from the National Health and Nutrition Examination Survey.

While understanding your body fat percentage may help reveal more about your disease risk than BMI or other measures, it's not without its flaws.

1. ‌It's not easy to measure.‌ Many body fat analyzers available for you to buy aren't very accurate, according to the Mayo Clinic. And the more accurate measures — such as getting weighed underwater — are complex and also typically require professionals along with their equipment.
2. ‌There isn't a consensus on healthy body fat‌ ‌percentage,‌ according to the University of Michigan Health — that is, unlike other methods with straightforward categories and rules, there isn't always a clear sense of what is (and isn't) a healthy percentage of body fat.

Health professionals, as well as health organizations around the world, focus a lot of attention on weight. That's not simply because it's readily visible: Weight is a key indicator of a person's health.

Since 1975, the rate of obesity around the world has tripled, according to the WHO — as of 2016 (the most recent year with available WHO data) there are more than 1.9 billion adults who have overweight and 650 million who have obesity.

There's typically less attention given to people who have underweight, but that condition is also associated with certain diseases and conditions.

"Obesity affects every organ, but diabetes and cardiovascular disease are the ones most likely to cause health issues," Dr. Ali says.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the health risks of having obesity or carrying too much weight include:

• Cancer
• Type 2 diabetes
• High blood pressure
• Heart disease
• Stroke
• Sleep apnea
• Metabolic syndrome
• Fatty liver disease
• Osteoarthritis disease
• Gallbladder disease
• Kidney disease
• Mental health problems, such as depression
• Pregnancy risks

Having slight overweight puts someone at risk for these health problems, per the WHO — and with more weight, the risk increases.

Reassuringly, the reverse can also be true: For instance, for people at risk of type 2 diabetes, losing about 5 percent of your body weight can help prevent the disease, according to the NIDDK. For some people, this could mean aiming to lose 1 to 2 pounds per week.

And, while it's challenging to know if losing weight will reduce a person's cancer risk, it's possible there's a relationship there — for instance, people who have bariatric surgery may have a lower risk of obesity-related cancers than people with obesity who do not have this surgery, according to the National Cancer Institute (NCI).

The major diseases — cancer, diabetes and so on — get a lot of attention when it comes to weight. But it's not just these conditions. Having overweight or obesity can reduce the quality of someone's life, per the CDC. It can make everyday things like traveling on an airplane stressful and expensive. It can lead to pain, trouble sleeping, changes to mood and energy levels and difficulty moving.

With more weight, people may have shortness of breath or decrease their activity, Dr. Ali says, which can in turn lead to other concerns.

There's less attention paid to people who have underweight compared to those who have obesity. Makes sense, when you consider the prevalence of the two: Only an estimated 1.5 percent of U.S. adults have underweight, according to the CDC. In comparison, 42 percent of adults in the U.S. have obesity, per the CDC.

But falling in the underweight category is not good for your health (despite many cultural cues, which tend to glorify leanness). It's associated with an increased risk of death compared to people who have normal weight, according to an April 2014 study in ‌BMJ Open‌, which looked at more than 30,000 people over several decades.

And, in an observational study of nearly half a million people, people who had underweight had a greater risk of heart disease than those with normal weight, according to research in the December 2017 issue of ‌Medicine‌. It's worth noting that the increased risk of people with underweight having heart disease was lower than that of people with overweight or obesity.

Using data from the 2012 Behavioral Risk Factor Surveillance System (BRFSS) from the CDC, researchers looked at the effects of having underweight for the May 2017 issue of the ‌Journal of Diabetes and Obesity‌ and concluded there were "similar negative health effects" for having underweight or obesity.

People who have underweight might not be getting the nutrients they need. Being malnourished can lead to many health problems, according to the American Academy of Family Physicians (AAFP), including:

• Fragile bones and osteoporosis
• A weakened immune system
• Anemia
• Fertility issues
• Hair loss

Some causes of underweight mirror the reasons for overweight: Genetics and medications, for instance, can be contributing factors. Other factors include being very active and psychological issues, such as depression or eating disorders. Having underweight can also be an early indicator of an illness, such as thyroid problems, diabetes or cancer, per the AAFP.