Ideal Weight Calculator

Determining your ideal weight involves far more complexity than simply consulting a chart or plugging numbers into a formula. While various mathematical equations provide baseline estimates, your optimal weight depends on body composition, frame size, muscle mass, health markers, and personal goals. Understanding different calculation methods and their limitations helps you establish realistic, healthy weight targets.

Healthy Weight Ranges vs. Single Values

Modern health organizations increasingly emphasize weight ranges rather than specific ideal weights. The WHO defines healthy BMI as 18.5 to 24.9, which translates to substantial weight ranges based on height. For someone 5'8" tall, healthy weight spans from 122 to 164 pounds, a 42-pound range.

This range accommodates variations in muscle mass, frame size, and body composition. An athletic individual with significant muscle might weigh 160 pounds at 5'8" with 12% body fat, falling at the upper end of healthy weight. A sedentary person at the same height might weigh 135 pounds with 25% body fat, occupying the lower end. Both fall within healthy BMI ranges, but their body compositions differ dramatically.

Body composition matters more than scale weight for health outcomes. Two people at identical heights and weights can have completely different health profiles based on their muscle-to-fat ratios. Someone carrying 25% body fat faces different health risks than someone at 15% body fat, regardless of whether their weight matches formula predictions.

Waist circumference provides additional context for healthy weight determination. Men with waist measurements exceeding 40 inches and women over 35 inches face increased health risks regardless of their weight or BMI. Conversely, someone slightly above their calculated ideal weight with a healthy waist circumference might be in excellent health.

Beyond the Scale

Ideal weight shouldn't be determined solely by mathematical formulas developed decades ago on limited populations. Your optimal weight is the weight at which you feel healthy, energetic, and strong while maintaining excellent metabolic markers and supporting your lifestyle and goals.

Progress photos often reveal changes that scale weight misses. Losing fat while building muscle might keep your weight stable, but your appearance, strength, and health improve dramatically. Circumference measurements of waist, hips, chest, arms, and thighs provide additional data points about body composition changes.

Regular health screenings including blood work, blood pressure monitoring, and cardiovascular fitness assessments offer objective health indicators independent of weight. These markers reveal whether your current weight supports optimal health or requires adjustment.

Your ideal weight is ultimately the weight you can maintain without extreme measures, while feeling energized, performing well, and exhibiting healthy metabolic markers. Formulas provide useful starting points for conversation, but your body's response to different weights provides the most accurate guidance for determining your personal ideal.

The Devine Formula

Dr. B.J. Devine developed his formula in 1974 primarily for medication dosing rather than health optimization. For men, the Devine formula calculates ideal weight as 50 kg + 2.3 kg per inch over 5 feet tall. For women, it's 45.5 kg + 2.3 kg per inch over 5 feet.

A man standing 5'10" (10 inches over 5 feet) would have a Devine ideal weight of 50 + (2.3 × 10) = 73 kg or approximately 161 pounds. A woman of the same height would calculate as 45.5 + (2.3 × 10) = 68.5 kg or roughly 151 pounds.

The Devine formula produces relatively lean weight estimates that work well for average-framed individuals with moderate muscle mass. However, it fails to account for body composition differences. A muscular athlete and sedentary person of identical height receive the same ideal weight recommendation, despite vastly different body compositions and health profiles.

Robinson and Miller Formulas

The Robinson formula, published in 1983, modified Devine's work. For men: 52 kg + 1.9 kg per inch over 5 feet. For women: 49 kg + 1.7 kg per inch over 5 feet. That same 5'10" man would have a Robinson ideal weight of 52 + (1.9 × 10) = 71 kg or 156 pounds, while the woman would be 49 + (1.7 × 10) = 66 kg or 145 pounds.

Robinson generally produces slightly lower estimates than Devine, particularly for taller individuals. The reduced per-inch multiplier creates more conservative weight recommendations that some researchers believe better reflect healthy weights for modern populations.

Dr. Miller proposed another variation in 1983. For men: 56.2 kg + 1.41 kg per inch over 5 feet. For women: 53.1 kg + 1.36 kg per inch over 5 feet. The 5'10" man's Miller ideal weight would be 56.2 + (1.41 × 10) = 70.3 kg or 155 pounds. The woman would calculate as 53.1 + (1.36 × 10) = 66.7 kg or 147 pounds.

These three formulas demonstrate the challenge of defining "ideal" weight mathematically. For the same 5'10" man, recommended weights range from 155 to 161 pounds, a six-pound spread. For the woman, the range spans 145 to 151 pounds. This variability underscores that ideal weight exists as a range rather than a precise number.

Factors Beyond the Formulas

Age influences optimal weight ranges, with research suggesting slightly higher weights in older adults may offer protective benefits. While unexplained weight loss in elderly populations often signals health decline, maintaining modest reserves can be beneficial. A 30-year-old and 70-year-old of the same height might have different optimal weights.

Muscle mass dramatically affects appropriate weight. Athletes, bodybuilders, and individuals engaged in regular resistance training naturally weigh more than sedentary counterparts of similar heights. A muscular individual might weigh 20-40 pounds more than formula predictions while maintaining single-digit body fat percentages.

Athletic performance goals influence ideal weight differently than pure health optimization. Distance runners often perform best at the lower end of healthy weight ranges, while strength athletes and contact sport participants excel with more mass. Someone training for a marathon might target different weights than someone powerlifting, even if they're the same height.

Medical history and metabolic health markers trump simple weight calculations. Blood pressure, cholesterol levels, fasting glucose, inflammatory markers, and insulin sensitivity indicate health status more accurately than scale weight. Someone slightly above their calculated ideal weight with excellent metabolic markers is healthier than someone at "ideal" weight with poor markers.

Frame Size Considerations

Frame size significantly influences healthy weight ranges, yet most formulas ignore this factor entirely. Someone with a large frame and thick bones naturally weighs more than a small-framed person of identical height, even at similar body fat percentages. Measuring wrist circumference or elbow breadth helps estimate frame size.

For wrist measurement, wrap your thumb and middle finger around your wrist at its smallest point. If your fingers overlap significantly, you likely have a small frame. Fingers just touching indicate medium frame. A gap between fingers suggests large frame. Men with wrists under 6.5 inches typically have small frames, 6.5-7.5 inches indicates medium, and over 7.5 inches suggests large frames. For women, under 5.5 inches is small, 5.5-6.5 is medium, and over 6.5 is large.

Frame size can justify 10-15 pounds of variation from formula predictions. A large-framed 5'10" man might healthily weigh 175 pounds while a small-framed man of the same height might optimize at 155 pounds. Both could have identical body fat percentages and health markers despite the 20-pound difference.

The Metropolitan Life Insurance tables from 1983 incorporated frame size into weight recommendations, providing ranges rather than single values. While outdated in some respects, this approach acknowledged that healthy weight exists across a spectrum influenced by structural factors beyond height alone.

Setting Realistic Weight Goals

Use formula calculations as starting points rather than definitive targets. If multiple formulas suggest 160-165 pounds for your height and sex, consider this your baseline estimate. Then adjust based on frame size, muscle mass, and personal factors. Add 5-10 pounds if you're large-framed or very muscular, subtract 5-10 pounds if you're small-framed.

Prioritize body composition goals over specific scale weights. Rather than fixating on reaching 155 pounds, focus on achieving a healthy body fat percentage between 10-20% for men or 18-28% for women. You might discover your ideal health and appearance occur at weights different from formula predictions.

Monitor health markers alongside weight. Track blood pressure, cholesterol, fasting glucose, and energy levels. If your weight falls slightly above calculated ideals but your health markers are excellent, you're likely at an appropriate weight for your body. Conversely, reaching your "ideal" weight while experiencing poor health markers suggests that weight isn't actually ideal for you.

Consider functional fitness and quality of life. Can you perform daily activities comfortably? Do you have energy for your lifestyle? Do you feel strong and capable? These qualitative assessments matter as much as quantitative weight measurements. Someone maintaining a weight that supports their active lifestyle and goals is at their ideal weight, regardless of formulas.