At a Glance: "Ideal body weight" is not a single number on a chart — it is a range that changes with your height, frame size, muscle mass, and age. This guide explains the most common formulas (Hamwi, Devine, BMI-based), why your ideal weight at 25 is not the same at 55, and how to find a realistic, healthy target that works for your body.
The number that is different for everyone — and that is okay
Two people can be 5'10" and 185 pounds. One is a muscular lifter with 15% body fat. The other is sedentary with 28% body fat. Their BMIs are identical — 26.5, officially "overweight." But their "ideal" weights are completely different.
That is the first thing to understand about ideal body weight: there is no single answer. But there are science-backed ways to find your personal range.
This guide walks you through the most trusted formulas, explains why muscle and age matter, and gives you a practical method to find your own ideal weight — not someone else's.
Common formulas for calculating ideal body weight
Doctors and researchers have developed several formulas over the years. They all give slightly different numbers, which tells you something important: the "right" weight is a range, not a precise point.
| Formula | Men | Women |
|---|---|---|
| Hamwi (1964) | 106 lb for 5ft + 6 lb per inch over | 100 lb for 5ft + 5 lb per inch over |
| Devine (1974) | 50 kg (110 lb) for 5ft + 2.3 kg (5 lb) per inch over | 45.5 kg (100 lb) for 5ft + 2.3 kg (5 lb) per inch over |
| Robinson (1983) | 52 kg (115 lb) + 1.9 kg (4.2 lb) per inch over 5ft | 49 kg (108 lb) + 1.7 kg (3.7 lb) per inch over 5ft |
| Miller (1983) | 56.2 kg (124 lb) + 1.41 kg (3.1 lb) per inch over 5ft | 53.1 kg (117 lb) + 1.36 kg (3 lb) per inch over 5ft |
Let us run an example for a 5'10" (70 inches) man:
Hamwi: 106 + (6 × 10) = 166 lb
Devine: 110 + (5 × 10) = 160 lb
Robinson: 115 + (4.2 × 10) = 157 lb
Miller: 124 + (3.1 × 10) = 155 lb
That is an 11-pound range — all considered "ideal" by different standards. So which one is right? None of them, exactly. They are starting points.
What the research says: A 2000 review in Annals of Pharmacotherapy (Pai & Paloucek, Vol. 34, Issue 9, pp. 1066-1069) traced the origin of these formulas and concluded that none were derived from healthy populations — most were created for estimating drug dosages. Use them as rough guides, not prescriptions.
Why your ideal weight changes with age
A 25-year-old and a 65-year-old can have the same height and weight but very different health profiles. As adults age, they naturally lose muscle (sarcopenia) and may gain fat even if the scale does not move. The CDC notes that BMI categories stay the same across adulthood, but body composition does not.
Metabolic rate also slows: resting energy expenditure drops by roughly 1-2% per decade after age 20. A person who could eat 2,500 calories at 30 without gaining may need only 2,200 at 50 to maintain the same weight. That is why weight often creeps up even when eating habits do not change.
For older adults, a slightly higher weight can actually be protective. A 2014 meta-analysis in the American Journal of Clinical Nutrition (Winter et al., Vol. 99, Issue 4, pp. 875-890) found that older adults (≥65 years) with a BMI in the 23-27 range had the lowest mortality risk — not the standard 18.5-24.9. The study concluded that carrying a few extra pounds provides nutritional reserves against illness, falls, and frailty.
So your ideal weight at 30 (maybe 165 lb at 5'10") might become 175 lb at 70 — and that could be perfectly healthy.
The missing piece: frame size and muscle mass
Two people can be 5'10" and 170 pounds. One has a small frame, narrow shoulders, and low muscle — they might actually be overfat. The other has a large frame, broad shoulders, and carries muscle — they could be lean and healthy.
That is why the formulas above use a simple height-weight calculation but ignore frame. A quick way to estimate your frame size: wrap your thumb and middle finger around your opposite wrist. If they overlap, you have a small frame. If they just touch, medium. If they do not touch, large frame.
For a large-framed man, add 5-10% to the formula numbers. For a small-framed man, subtract 5-10%.
Muscle mass is even more important. A body fat calculator gives you a better picture than any weight formula. For men, a healthy body fat range is roughly 15-20% for fitness, 21-25% for acceptable. If your body fat is in check, do not worry if your weight is slightly above a formula's "ideal."
A simpler method: BMI-based ideal weight range
Because BMI has well-defined healthy ranges (18.5-24.9), you can reverse-engineer an ideal weight range from your height. Here is how:
Lower bound (BMI 18.5): 18.5 × (height in meters)²
Upper bound (BMI 24.9): 24.9 × (height in meters)²
For a 5'10" man (1.78 m):
Lower: 18.5 × (1.78 × 1.78) = 18.5 × 3.17 = 58.6 kg ≈ 129 lb
Upper: 24.9 × 3.17 = 78.9 kg ≈ 174 lb
That is a 45-pound range — much wider than the formula numbers. But it accounts for individual differences. Most healthy people at 5'10" fall between 145 and 175 pounds.
If you lift weights or have a large frame, aim for the higher end. If you are sedentary or small-framed, the lower end makes sense.
Four examples: finding your personal ideal weight
Case 1 — Active, muscular man, 40 years old, 5'10": Devine formula says 160 lb. But he lifts weights, has a large frame, and 15% body fat. He feels great at 180 lb. His ideal weight: 175-185 lb. Ignore the lower numbers.
Case 2 — Sedentary desk worker, 45 years old, 5'10": Same height. He does not exercise, has a small frame, and his body fat is 28%. The formula says 160 lb, but he is currently 190 lb. His ideal weight target: 155-165 lb, while adding protein and resistance training to preserve muscle.
Case 3 — Senior man, 68 years old, 5'9": Hamwi formula gives 160 lb. But he has good mobility, a 36-inch waist, and eats well. He is 175 lb. For his age, that weight is protective. His doctor agrees — no weight loss needed.
Case 4 — Young athlete, 25 years old, 6'1": Miller formula suggests 180 lb. He is a collegiate swimmer, 195 lb, body fat 11%. His ideal weight is actually higher than the formula — muscle matters.
The common thread: formulas are just starting points. You have to adjust for frame, muscle, age, and how you feel.
Your 3-step plan to find your ideal weight
Instead of obsessing over one number, do this:
Step 1 — Calculate your BMI-based range. Use the formula above or an online BMI calculator. That gives you a healthy weight zone.
Step 2 — Estimate your body fat percentage. Use a body fat calculator, calipers, or waist measurement. If your body fat is in the fitness range (under 20% for men 30-50), you are likely fine even at the higher end of the BMI range.
Step 3 — Check your waist circumference. Under 37 inches? Low risk. 37-40 inches? Moderate risk — consider losing a few pounds. Over 40 inches? High risk — weight loss and exercise are priorities.
Do this every 3-6 months. Your ideal weight may shift as you gain muscle or age. That is normal.
Common myths about ideal body weight
Myth: There is one perfect weight for your height. Fact: A 30-pound range is normal and healthy, depending on frame and muscle.
Myth: You should weigh what you did in high school. Fact: Most adults gain 10-20 pounds of healthy weight — bone density, organ weight, and yes, some fat — by middle age. Do not chase teenage numbers.
Myth: Ideal weight formulas work for everyone. Fact: They were developed for specific populations (often hospitalized patients) and do not account for athletes or older adults.
Myth: Losing weight is always the answer. Fact: For adults over 65, a stable weight in the higher range is often healthier than losing pounds and risking frailty.
Final thoughts: your ideal weight is a moving target — and that is fine
Forget the idea of a single magic number. Your healthy weight range will change as you age, build muscle, or recover from illness. Use the BMI range as a broad guide, add body fat and waist measurements for precision, and adjust for your frame and activity level.
The best "ideal weight" is the one where you have good energy, healthy blood work, and a waist under 40 inches — and where you do not have to starve or over-exercise to stay there.
Frequently Asked Questions About Ideal Body Weight
What is the most accurate ideal body weight formula?
None is perfectly accurate. The Devine formula is most commonly used in medicine, but it was originally developed to calculate drug dosages, not healthy weights. The BMI-based range is more flexible and accounts for individual variation.
How much should a 5'10" male weigh?
A healthy range is roughly 145-175 lb, but a muscular man can be 185 lb with low body fat. A sedentary man with a small frame might be healthiest at 150-160 lb. Use body fat percentage and waist size as your real guides.
Does ideal weight increase with age?
Yes, slightly. Most adults gain 1-2 pounds per year from early adulthood to middle age, partly due to metabolism slowing (1-2% per decade) and muscle loss. A weight that is healthy at 30 may be underweight at 70. For seniors, a BMI of 23-27 is often better than 18.5-24.9, as shown by the Winter et al. meta-analysis.
How do I know if I am at my ideal weight without a doctor?
Check three things: waist circumference (under 37 inches for low risk), body fat percentage (under 22% for acceptable), and how you feel (energy, strength, blood pressure if you know it). If those are good, do not worry about the scale.
Should I use ideal weight formulas if I am an athlete?
No. Those formulas will almost certainly underestimate your healthy weight because they do not account for muscle. Use body fat percentage (6-15% for male athletes is typical) and performance metrics instead.
Content Integrity Review: This article has been reviewed for alignment with CDC adult BMI classification standards, WHO global BMI guidelines, NIH waist circumference and health risk protocols, Academy of Nutrition and Dietetics position papers on weight management, and peer-reviewed literature on ideal body weight formulas and body composition assessment. Individual health decisions should always be made with a qualified healthcare provider.
Developed using: CDC adult BMI screening standards, WHO global obesity guidelines, NIH waist circumference protocols, and peer-reviewed meta-analyses on BMI and mortality in older adults (Winter et al., 2014).
References & Sources
NIH: Assessing Your Weight and Health Risk — waist circumference
Academy of Nutrition and Dietetics — official position on weight management
Pai MP, Paloucek FP. The origin of the "ideal" body weight equations. Ann Pharmacother. 2000;34(9):1066-9. DOI: 10.1345/aph.19381
Winter JE, et al. BMI and all-cause mortality in older adults: a meta-analysis. Am J Clin Nutr. 2014;99(4):875-90. DOI: 10.3945/ajcn.113.068122
BMI Calculator Blog. This content is provided for educational and informational purposes only. We encourage sharing with proper attribution to our site. Unauthorized commercial use is prohibited. Medical Disclaimer: This content does not replace professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified physician or other licensed health provider with any questions regarding your body composition, weight status, or health goals.