For a 5’8 woman, a healthy weight falls roughly between 125 and 163 pounds based on standard BMI guidelines. That range corresponds to a BMI of about 19 to 24.9, which is the bracket most health organizations classify as “normal weight.” But that 38-pound spread is wide for a reason: your body frame, muscle mass, age, and where you carry fat all influence what “healthy” actually looks like for you.
The Standard BMI Range at 5’8
BMI, or body mass index, is a simple ratio of weight to height. For a woman who stands 5 feet 8 inches tall, here’s how the scale breaks down:
- BMI 19: 125 lbs
- BMI 20: 131 lbs
- BMI 21: 138 lbs
- BMI 22: 144 lbs
- BMI 23: 151 lbs
- BMI 24: 158 lbs
- BMI 25: 164 lbs (starts the “overweight” category)
A BMI below 18.5, which would be under roughly 122 pounds at this height, is considered underweight. Above 25 tips into overweight, and above 30 (about 197 pounds) is classified as obese. These cutoffs are population-level guidelines, not personalized diagnoses. They’re a useful starting point, but they don’t tell the whole story.
How Body Frame Changes the Target
One of the simplest ways clinicians estimate an individual ideal weight is the Hamwi formula. For women, it starts with 100 pounds for the first 5 feet of height, then adds 5 pounds for each additional inch. At 5’8, that puts the baseline at 140 pounds. From there, you adjust by about 10 percent depending on your frame size:
- Small frame: ~126 lbs
- Medium frame: ~140 lbs
- Large frame: ~154 lbs
A quick way to estimate your frame size is to wrap your thumb and middle finger around your opposite wrist. If your fingers overlap, you likely have a small frame. If they just touch, medium. If there’s a gap, large. This is an approximation, but it helps explain why two women at the same height can look and feel healthy at very different weights. A large-framed woman at 154 pounds may carry that weight with strong bones and solid muscle, while a small-framed woman at the same weight might feel heavy.
Why the Number on the Scale Can Be Misleading
BMI treats all weight the same, whether it comes from muscle, bone, or fat. That’s a significant blind spot. A study published in Medicine & Science in Sports & Exercise looked at female elite athletes whose BMI fell in the normal range (18.5 to 24.9) and found that nearly 7 percent of them had body fat levels high enough to qualify as obese, while 2 percent had dangerously low body fat. In other words, their weight looked fine on paper, but their body composition told a completely different story.
This applies to non-athletes too. If you strength train regularly or carry above-average muscle mass, you could weigh 165 or 170 pounds at 5’8 and still be in excellent metabolic health. Conversely, someone at 140 pounds with very little muscle and a high percentage of body fat, sometimes called “normal weight obesity,” can face real health risks that the scale completely misses.
Body Fat Percentage as a Better Gauge
Because scale weight can’t distinguish muscle from fat, body fat percentage gives you a clearer picture. For women, a healthy body fat range is generally 25 to 31 percent. Women who are very active or athletic often sit lower, in the 18 to 24 percent range. Below about 12 percent is considered essential fat, the minimum your body needs for hormonal function, and dropping below it carries serious health consequences including loss of menstrual cycles and bone density.
You can get a rough body fat estimate through methods like bioelectrical impedance scales (common bathroom smart scales), skinfold calipers, or more precise tools like a DEXA scan. None of these are perfect, but tracking body fat over time gives you more useful information than tracking weight alone.
Waist Size Matters More Than You’d Think
Where you carry fat may matter even more than how much you weigh. Fat stored around your midsection (visceral fat) wraps around internal organs and drives up risk for heart disease, type 2 diabetes, and metabolic syndrome. Fat stored in your hips and thighs carries far less metabolic risk.
The NHS recommends keeping your waist circumference to less than half your height. At 5’8 (68 inches), that means your waist should ideally stay under 34 inches. This is a quick, free measurement you can do at home with a tape measure placed just above your hip bones. If your weight is in the “normal” BMI range but your waist exceeds that threshold, it’s worth paying attention to. And if your BMI is technically in the overweight category but your waist-to-height ratio is healthy, that’s a reassuring sign.
Age Shifts the Equation
Standard BMI guidelines were developed primarily around younger and middle-aged adults. For women over 65, the picture changes significantly. Research published in the Annals of Geriatric Medicine and Research found that older adults with a BMI under 25 actually faced higher risks of falls, reduced muscle strength, balance problems, and malnutrition. The study concluded that the optimal BMI for older women may be around 31 to 32, well above what’s considered “normal” for younger adults.
This makes biological sense. As you age, maintaining muscle mass and bone density becomes critical for preventing fractures and preserving independence. Carrying some extra weight appears to provide a protective buffer. A 5’8 woman over 65 who weighs 175 or even 190 pounds may be in a healthier position than one who weighs 135 and has lost significant muscle. For older women, being underweight is often a bigger threat than being moderately overweight.
Putting It All Together
If you’re a 5’8 woman looking for a single number, the midpoint of the BMI range lands around 140 to 145 pounds, which aligns closely with the Hamwi formula’s estimate for a medium frame. But the practical answer is a range: roughly 125 to 163 pounds for most adults under 65, adjusted upward if you’re older, more muscular, or have a larger frame.
The most useful approach is to look at multiple signals rather than fixating on weight alone. A healthy body fat percentage (25 to 31 percent for most women), a waist measurement under 34 inches, good energy levels, regular menstrual cycles, and normal blood pressure and blood sugar collectively paint a much more accurate picture of health than any single number on a scale ever could.