For most adults, a healthy weight is the range that puts your body mass index (BMI) between 18.5 and 24.9 — roughly 115–154 lb (52–70 kg) at 5'6" or 129–174 lb (58.5–78.7 kg) at 5'10". If you have ever typed "how much should I weigh" into a search bar, you have probably noticed that every chart gives a slightly different answer. That is not sloppiness — there genuinely is no single ideal number. What science offers instead is a healthy range for your height, a couple of formulas with surprisingly practical origins, and a handful of measurements that say more about your health than the scale ever will. This guide walks through all of it, with the math shown.
The honest answer: there is no one perfect number
Two people of the same height can both be healthy at noticeably different weights. Bone structure, muscle mass, fat distribution, age, sex, and genetics all shift what a healthy weight looks like for an individual. That is why major health bodies such as the CDC and the World Health Organization do not publish a single target weight — they describe a healthy weight range, most commonly defined using body mass index (BMI).
That reframing is worth sitting with for a second. A range means there is no prize for landing on one exact number, and no failure in sitting a few pounds to either side of a chart's midpoint. The useful question is not "what should I weigh?" so much as "is my weight, along with my other health markers, in a place that supports how I want to live?"
The healthy BMI weight range for your height
BMI is your weight in kilograms divided by the square of your height in meters. For adults aged 20 and over, the CDC classifies a BMI of 18.5 to 24.9 as the healthy weight category. You can flip that around to get a weight range for any height: multiply 18.5 and 24.9 by your height in meters, squared.
Take someone who is 5'6" (1.676 m). Squaring the height gives about 2.81, so the range runs from roughly 52 kg (18.5 × 2.81) up to about 70 kg (24.9 × 2.81) — approximately 115 to 154 pounds. Here is that same calculation done for a spread of common heights:
| Height | Healthy range (lb) | Healthy range (kg) |
|---|---|---|
| 5'0" (1.52 m) | 95–127 | 43.0–57.8 |
| 5'2" (1.57 m) | 101–136 | 45.9–61.8 |
| 5'4" (1.63 m) | 108–145 | 48.9–65.8 |
| 5'6" (1.68 m) | 115–154 | 52.0–70.0 |
| 5'8" (1.73 m) | 122–164 | 55.2–74.3 |
| 5'10" (1.78 m) | 129–174 | 58.5–78.7 |
| 6'0" (1.83 m) | 136–184 | 61.9–83.3 |
| 6'2" (1.88 m) | 144–194 | 65.4–88.0 |
Weight ranges corresponding to a BMI of 18.5–24.9, calculated as BMI × height in meters squared. Pounds are rounded to the nearest whole number.
Notice how wide each band is — about 50 pounds at the taller heights. That width is the point: it reflects real, healthy variation between bodies. To see exactly where you fall, our BMI calculator does the conversion for you and shows your number in context.
The Devine formula: an "ideal weight" born in the pharmacy
Many ideal-weight tools are built on the Devine formula, and its origin story explains a lot about how it should be used. In 1974, Dr. B. J. Devine published the equation not as a wellness target but as a shortcut for physicians dosing medications — notably the antibiotic gentamicin — whose distribution in the body tracks lean mass better than total weight. The formula was an educated clinical estimate, not the product of a large population health study.
The math is simple. Men start at 50 kg and add 2.3 kg for every inch of height over 5 feet; women start at 45.5 kg and add the same 2.3 kg per inch. A 5'10" man works out to 50 + (2.3 × 10) = 73 kg, or about 161 pounds. A 5'4" woman comes to 45.5 + (2.3 × 4) = 54.7 kg, roughly 121 pounds. Both figures land inside the healthy BMI ranges above, though at different points — the men's formula tends to sit higher in the range than the women's.
Our ideal weight calculator runs Devine alongside several other published formulas so you can see how much they disagree with each other. That disagreement is informative: when respected equations give different "ideals," the sensible takeaway is to treat each as a reference point on a map, not a destination you must reach.
Why frame size and muscle move the goalposts
Neither BMI nor Devine can see what your weight is made of. Muscle is denser than fat, so a strength athlete can carry a BMI of 26 or 27 with a lean, healthy body composition — the number flags them as "overweight" while their actual fat mass is low. The reverse also happens: someone can sit comfortably inside the healthy BMI range while carrying relatively little muscle and more fat than is ideal, which is one reason BMI is considered a screening tool rather than a diagnosis.
Frame size matters too. Older height-weight charts, like the Metropolitan Life tables from the mid-20th century, tried to account for small, medium, and large frames — judged by measurements such as elbow breadth or wrist size. The adjustments were crude, but the instinct was right: a broad-shouldered, large-boned person will naturally and healthily weigh more than a fine-boned person of identical height. If your build sits at either end of that spectrum, expect your comfortable, healthy weight to sit toward the corresponding end of your BMI range.
Better signals than the number on the scale
If the scale is a blunt instrument, these measures add the missing detail.
Waist circumference
Fat stored around the abdomen is more strongly linked to heart disease and type 2 diabetes than fat stored elsewhere. Per National Institutes of Health guidance, risk rises when waist circumference exceeds 40 inches (102 cm) in men or 35 inches (88 cm) in women — a check worth doing even when BMI looks fine.
Waist-to-hip ratio
Comparing your waist to your hips captures fat distribution, not just size. A World Health Organization expert consultation set the abdominal obesity thresholds at a ratio of 0.90 or higher for men and 0.85 or higher for women. Our waist-to-hip ratio calculator walks you through measuring correctly and interprets the result.
Body fat percentage
Two people at the same weight can differ dramatically in body composition. Estimating your body fat percentage — even roughly, with a tape-measure method like the one in our body fat calculator — tells you whether weight change is coming from fat, muscle, or both.
Trends, not snapshots
Day-to-day weight swings with water, food timing, sodium, and hormones, often by several pounds. A single weigh-in is noise; a weekly average tracked over months is signal. Pair the trend with how you feel — energy, sleep, strength, lab results — and you get a far richer picture than any one morning on the scale.
When to talk to a professional
Some situations deserve a real conversation rather than a calculator: unintentional weight loss or gain, weight concerns during pregnancy or while managing a medical condition, planning a significant weight change, or noticing that thoughts about food and weight are taking up more mental space than feels healthy. A physician or registered dietitian can look at your full history and bloodwork — context no formula has. Everything in this guide is educational information, not medical advice, and it is not a substitute for care from a professional who knows you.
The bottom line: your healthiest weight is a range, not a bullseye. Find your range, check the signals that matter more than the scale, and let the trend — not any single number — tell the story.
Sources: Centers for Disease Control and Prevention (Adult BMI Categories); National Heart, Lung, and Blood Institute / NIH (Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults); World Health Organization (Waist Circumference and Waist–Hip Ratio: Report of a WHO Expert Consultation, 2008; published 2011); Devine BJ, "Gentamicin therapy," Drug Intelligence and Clinical Pharmacy, 1974.