There’s no single formula that spits out the “right” goal weight for everyone. Instead, several well-established methods exist, each using different inputs like height, body frame, or body composition. The most useful approach is to triangulate: use two or three of these methods, see where the ranges overlap, and land on a realistic target that accounts for your individual build.
Start With BMI as a Rough Range
The quickest way to find a ballpark goal weight is to work backward from BMI. The World Health Organization defines a healthy BMI as 18.5 to 24.9, with 25 and above classified as overweight and 30 and above as obese. To find the weight range that keeps you in the healthy zone, use this formula:
Weight (in pounds) = BMI × height (in inches) squared ÷ 703
So for someone who is 5’6″ (66 inches), a healthy BMI range translates to roughly 115 to 154 pounds. That’s a 39-pound spread, which is why BMI alone isn’t enough to pick a specific goal. It gives you the boundaries, not the target.
BMI also has a well-documented blind spot: it can’t tell the difference between muscle and fat. About 41% of people classified as “nonobese” by BMI actually carry excess body fat when measured with more precise tools like a DEXA scan. The reverse is also true. People with significant muscle mass often register as overweight despite being lean. Think of BMI as the starting frame, not the finished picture.
Classic Ideal Body Weight Formulas
Several named formulas have been used in clinical settings for decades to estimate ideal body weight (IBW). They all follow a similar structure: assign a base weight for the first 5 feet of height, then add a set amount per additional inch. The differences between them come down to how much weight each formula adds per inch, which is why they produce slightly different numbers for the same person.
Here are the four most commonly referenced formulas. All assume a medium body frame.
- Hamwi: Men start at 106 lbs for 5 feet, adding 6 lbs per inch. Women start at 100 lbs for 5 feet, adding 5 lbs per inch.
- Devine: Men start at 110 lbs for 5 feet, adding 5.1 lbs per inch. Women start at 100 lbs for 5 feet, adding 5.1 lbs per inch.
- Robinson: Men start at 114 lbs for 5 feet, adding 4.2 lbs per inch. Women start at 108 lbs for 5 feet, adding 3.7 lbs per inch.
- Miller: Men start at 124 lbs for 5 feet, adding 3.1 lbs per inch. Women start at 110 lbs for 5 feet, adding 2.6 lbs per inch.
For a woman who is 5’5″, these formulas produce targets ranging from about 123 to 125 pounds, depending on which one you use. For a man at 5’10”, the range is roughly 149 to 166 pounds. The spread between formulas grows wider as height increases.
A practical approach: calculate your result from two or three of these formulas and average them. That midpoint is a reasonable starting estimate for someone with a medium frame.
Adjusting for Body Frame Size
The classic formulas assume a medium frame, but bone structure varies. A large-framed person will naturally weigh more than a small-framed person at the same height, even at the same body fat level. You can estimate your frame size by measuring your wrist circumference with a flexible tape measure.
For women under 5’2″, a wrist smaller than 5.5 inches indicates a small frame, 5.5 to 5.75 inches is medium, and over 5.75 is large. For women between 5’2″ and 5’5″, the cutoffs shift to under 6 inches (small), 6 to 6.25 inches (medium), and over 6.25 inches (large). For women over 5’5″, small is under 6.25 inches, medium is 6.25 to 6.5, and large is over 6.5.
For men over 5’5″, a wrist of 5.5 to 6.5 inches suggests a small frame, 6.5 to 7.5 inches is medium, and over 7.5 is large.
Once you know your frame size, adjust your ideal weight estimate by roughly 10%. Subtract 10% for a small frame, keep it as-is for medium, and add 10% for a large frame. If your average formula result was 150 pounds and you have a large frame, a goal closer to 165 makes more sense.
Using Body Fat Percentage Instead
A completely different way to set a goal weight is to focus on body composition rather than total pounds. This approach answers a better question: instead of “how much should I weigh?” it asks “how much of my weight should be fat?”
General fitness guidelines place healthy body fat at roughly 14 to 24% for men and 21 to 35% for women, with the ranges shifting upward slightly with age. If you know your current body fat percentage (from a DEXA scan, calipers, or a bioelectrical impedance scale), you can calculate a goal weight for any target body fat level.
The formula works like this:
First, find your lean mass: current weight × (1 minus current body fat as a decimal). If you weigh 180 pounds at 30% body fat, your lean mass is 180 × 0.70 = 126 pounds.
Then, divide lean mass by (1 minus your target body fat). If your target is 22% body fat: 126 ÷ 0.78 = about 162 pounds.
This method has a major advantage over height-based formulas because it accounts for muscle. Two people at 5’8″ could have wildly different ideal weights if one carries substantially more muscle. The body fat method respects that difference. Its main limitation is that you need a reasonably accurate starting measurement, and consumer-grade tools like bathroom scales with body fat sensors can be off by several percentage points.
Waist-to-Height Ratio as a Reality Check
Once you’ve picked a goal weight, the waist-to-height ratio offers a simple way to check whether you’re actually in a healthy range as you progress. The rule is straightforward: keep your waist circumference below half your height. A universal cutoff of 0.5 works across genders and ethnic groups as a marker of healthy central body fat.
Measure your waist at the narrowest point (usually at or just above the navel) and divide by your height, both in the same units. If you’re 68 inches tall and your waist is 33 inches, your ratio is 0.49, which falls just under the threshold. A ratio above 0.5 signals elevated risk for heart disease and metabolic problems. Above 0.6 puts you in a higher-risk category, and research has found that a ratio above 0.65 in adults under 40 is associated with a 139% greater risk of early death compared to those below 0.5.
This metric is especially useful because it captures something BMI and weight formulas miss entirely: where your body stores fat. Someone at a “healthy” weight who carries fat around the midsection may still face real health risks that a scale won’t reveal.
Putting It All Together
The most reliable goal weight comes from layering methods rather than relying on any single one. Start by running two or three of the classic formulas and adjusting for your frame size. Check the result against a healthy BMI range to make sure it falls within bounds. If you have access to a body fat measurement, use the body composition formula to see if the numbers align. As you make progress, track your waist-to-height ratio alongside the scale.
Keep in mind that these tools produce estimates, not prescriptions. Your body’s comfortable, sustainable weight may sit a few pounds above or below the calculated number. A weight where your energy is good, your bloodwork is healthy, and your waist stays below half your height is, for most people, the right goal, regardless of what a formula says it “should” be.