Healthy Weight Calculator

What is a Healthy Weight?

For adults, health agencies including the World Health Organization and the CDC define a healthy weight as one that gives a body mass index (BMI) of 18.5 to just under 25. Because BMI is weight divided by height squared, the healthy range in pounds or kilograms grows with height. For someone 5 feet 10 inches tall it spans about 129 to 174 pounds. The range is deliberately wide: people with more muscle or a larger frame are often healthy near the top, and smaller-framed people near the bottom. BMI is a screening tool rather than a diagnosis, so it works best combined with waist size and other health measures.

Healthy weight = 18.5 × height (m)² to 25 × height (m)²

In US units: weight (lb) = BMI × height (in)² ÷ 703.

Effects of Being Underweight, Overweight, and Obese

Being underweight, with a BMI below 18.5, can reflect not getting enough energy or nutrients, or an underlying illness. It is linked to a weakened immune system and more frequent infections, anemia, thinning bones and a higher risk of fractures, hair loss, fatigue, and disrupted menstrual cycles and fertility problems in women. In older adults, low weight is associated with frailty and a higher risk of death after illness or surgery. Unexplained weight loss should always be checked by a doctor, and very low weight can be a sign of an eating disorder.

Overweight, a BMI from 25 to 29.9, and obesity, a BMI of 30 or more, raise the risk of many chronic conditions. Excess body fat, especially fat stored around the waist, contributes to high blood pressure, unhealthy cholesterol and triglyceride levels and insulin resistance. Over time these raise the chances of type 2 diabetes, coronary heart disease and stroke.

Obesity is also linked to fatty liver disease, gallstones, osteoarthritis of the knees and hips, sleep apnea, gout, kidney disease and several types of cancer, including colorectal, endometrial, postmenopausal breast, kidney and esophageal cancers. In pregnancy, it raises the chances of gestational diabetes and preeclampsia.

The effects are not only physical. Higher weight is associated with chronic pain, reduced mobility and, partly because of stigma, depression and anxiety. Risk generally rises along with BMI and waist circumference, but it is not destiny: genetics, fitness, diet quality, sleep and smoking all matter too, and some people at a higher BMI have healthy blood pressure, blood sugar and cholesterol.

The encouraging news is that modest changes help. For people with overweight or obesity, losing 5% to 10% of body weight can lower blood pressure and blood sugar, improve cholesterol and reduce the risk of developing type 2 diabetes. For people who are underweight, regaining weight under medical guidance can restore bone health and hormonal balance.

Maintaining a Healthy Weight

Keeping weight in a healthy range comes down to balancing the energy you take in with the energy you use, but the habits that make this sustainable matter more than any single diet. Building meals around vegetables, fruit, whole grains, legumes, nuts and lean proteins supplies fiber and protein that keep you full on fewer calories. Limiting sugary drinks, alcohol and highly processed snacks removes many calories that do little to satisfy hunger.

Regular physical activity supports weight maintenance and benefits health at any weight. US guidelines recommend at least 150 minutes a week of moderate aerobic activity, such as brisk walking, plus muscle-strengthening exercise on two or more days. People maintaining a large weight loss often need more, around 60 minutes a day.

Sleep and stress also play a part: short sleep is linked to increased appetite and weight gain. Weighing yourself regularly helps catch small gains before they add up. Waist size is a useful companion to the scale; the thresholds below mark a substantially higher risk of metabolic disease.

Frequently asked questions

Sources

• CDC – About Adult BMI
• NIH NHLBI – Aim for a Healthy Weight
• WHO – Obesity and overweight