There’s no single number that applies to every 23-year-old woman. Your healthy weight depends almost entirely on your height. A 5’2″ woman and a 5’8″ woman will have very different target ranges. The standard tool for figuring out where you fall is BMI (body mass index), which maps your weight against your height. A BMI between 18.5 and 24.9 is considered healthy for adults.
Healthy Weight Ranges by Height
The National Heart, Lung, and Blood Institute publishes a BMI table that translates those BMI numbers into actual pound ranges for each height. For a BMI of roughly 19 to 24, here’s what that looks like:
- 5’0″: 97–123 lbs
- 5’1″: 100–127 lbs
- 5’2″: 104–131 lbs
- 5’3″: 107–135 lbs
- 5’4″: 110–140 lbs
- 5’5″: 114–144 lbs
- 5’6″: 118–148 lbs
- 5’7″: 121–153 lbs
- 5’8″: 125–158 lbs
- 5’9″: 128–162 lbs
- 5’10”: 132–167 lbs
- 5’11”: 136–172 lbs
- 6’0″: 140–177 lbs
Notice how wide each range is. A 5’5″ woman can weigh anywhere from 114 to 144 pounds and still fall in the healthy category. That 30-pound spread exists because people carry weight differently depending on muscle mass, bone density, and frame size.
How the Average Compares
The average weight of American women aged 20 to 29 is about 165 pounds. That number is well above the healthy BMI range for most heights on the chart, which reflects broader population trends rather than a medical target. “Average” and “healthy” are not the same thing here, so don’t use the national average as your personal benchmark.
A Quick Formula Doctors Use
Clinicians sometimes estimate a baseline weight using the Hamwi formula: start at 100 pounds for the first 5 feet of height, then add 5 pounds for every additional inch. So a 5’5″ woman would get a baseline of about 125 pounds. This is a rough midpoint, not a prescription. Most people fall naturally somewhere above or below it, and the BMI range above gives you the fuller picture.
Why BMI Doesn’t Tell the Whole Story
BMI treats all weight the same, whether it comes from muscle or fat. Research on female college athletes found that their BMI was statistically similar to non-athletes, yet their body fat percentage was about 4.4% lower. Athletes with high muscle mass, particularly in sports like basketball, are routinely misclassified as overweight or obese by BMI alone. If you strength train regularly or play a sport, your scale weight may sit higher than the chart suggests while your actual health markers are excellent.
Waist circumference is one useful complement to the scale. A large study reported by Mayo Clinic found that women with a waist of 37 inches or more had roughly 80% higher mortality risk than those at 27 inches or less, and every additional 2 inches of waist size increased risk by about 9%. This held true even among people whose BMI looked normal, which means where you carry fat matters just as much as how much you weigh.
Risks of Weighing Too Little
At 23, being underweight carries some risks that are easy to overlook. Low body weight in young women is linked to missed or irregular periods, reduced fertility, and complications during pregnancy including premature birth and low birth weight babies. It also affects your skeleton: inadequate weight during your twenties reduces bone mass at a time when your body is still building its peak bone density. That lost ground raises your risk of osteoporosis and fractures later in life. Persistent undereating can also tip into disordered eating patterns that become harder to reverse over time.
Risks of Weighing Too Much
Carrying significant excess weight in your early twenties gives those health consequences more years to accumulate. Excess body fat drives chronic inflammation and metabolic changes that increase the risk of high blood pressure, high cholesterol, type 2 diabetes, heart disease, stroke, and fatty liver disease. The CDC notes that risks climb with both the amount of excess weight and the duration you carry it, which means your twenties are a particularly high-leverage time to address it.
Finding Your Own Target
Start with the height-based chart above and see where you land. If you’re inside the range and feel strong, sleep well, have regular menstrual cycles, and your energy is steady through the day, you’re likely in a good spot. If you’re outside the range in either direction, the numbers above give you a reasonable zone to work toward gradually.
Keep in mind that the “right” weight for you may sit at the lower end, the upper end, or the middle of that range depending on your build and activity level. A 5’6″ woman who lifts weights four days a week will carry more lean mass and may sit comfortably at 145 pounds, while someone of the same height with a smaller frame might feel best at 125. Both can be perfectly healthy. The range exists for exactly this reason.