Ideal Weight Calculator: Find Your Healthy Weight by Height | Free

A Each formula was developed for different populations. Devine was originally for drug dosing, Robinson came from life insurance data. So they give different numbers. For a 5'6" woman, the range might span from 120 to 140 lbs depending on which method you pick. That's normal. Look at the spread across all formulas rather than fixating on one result.

A No, you shouldn't. Pregnancy and breastfeeding change your body's needs dramatically. These formulas assume a non-pregnant adult body composition. A woman who's 5'5" and pregnant might see a 'healthy' range of 114-144 lbs from the Devine formula, but that'd be dangerously low during gestation. Your doctor uses entirely different weight-gain charts — typically 25-35 lbs for a healthy BMI pregnancy. Don't substitute this calculator for prenatal care.

A No, it shows where the formulas say you should be, not where you actually are. Enter your height and gender, and you'll get weights from five methods. A 5'9" man might see 155 lbs from Hamwi but 169 lbs from Miller. Compare those to your current weight. If you're within 10 lbs of the range, you're close. This isn't a health checkup, just a reference. Use a full BMI or body fat test for real assessment.

A No, it doesn't. The Devine, Robinson, Miller, Hamwi, and BMI formulas all ignore age entirely. A 25-year-old and a 65-year-old with the same height and gender get identical results. That's a known limitation. Metabolism and muscle mass change with decades, but these equations never account for it. For older adults, especially over 60, the calculated numbers might underestimate a healthy weight. Use the lower end of the BMI range if you're concerned about frailty, or see your doctor.

A Don't panic over a 15-pound gap between Devine and BMI. That spread is normal and actually useful. Look at the lowest and highest numbers, then treat everything between them as your acceptable zone. For a 5'8" man, that might be 140 to 160 lbs depending on frame size. If your current weight sits inside that range, you're likely in a reasonable spot. If you're outside it, focus on the middle value as your target. No single formula is perfect, so a range beats a single number.

A No, and that surprises most people. These five formulas only look at height and gender. A 5'10" person with a small frame gets the same number as someone with a large frame. Wrist circumference can vary by 1.5 inches between frames, which throws off any single estimate. The Hamwi method was actually designed with an assumption of medium frame, but it still doesn't let you tweak it. So your best move is to use the full range across all formulas instead of picking a pinpoint number. Treat the middle as a guide, not a verdict.

A Then the formulas aren't wrong, but they're incomplete. Your ideal weight range is a statistical guess based on height, not a measure of health. A 5'7" woman might hit 130 lbs from the Miller formula and still have high blood pressure or low energy. Those numbers ignore waist circumference, sleep quality, cholesterol, and strength. Use the calculator as one data point, then add other metrics like body fat percentage and resting heart rate. Get a blood panel done if you can. That'll tell you more than any equation.

A Not even close. These five formulas were built from population averages, so a 5'10" man might see 150 lbs from Devine and 166 lbs from Miller. That's a 16-pound spread on the same body. Nobody can pin your ideal weight to a single digit, and any calculator claiming otherwise is selling you something. Treat the range as your answer, then sanity-check it against how you actually feel and perform.

A Each method comes from a completely different medical era. Hamwi built his formula in 1964 for quick clinical dosing, while Devine created his in 1974 specifically to calculate antibiotic dosages for hospital patients. For a 5'10" male, Hamwi usually outputs about 166 lbs, whereas Devine lands closer to 155 lbs. That eleven-pound gap exists because they were never meant to judge personal fitness. Take the average of both numbers instead of stressing over the difference.

A That happens constantly with muscular users. A 5'10" runner weighing 175 lbs will see warnings that they're 'overweight' by Devine or Miller formulas. Muscle weighs significantly more than fat by volume. These equations assume an average sedentary body composition from decades ago. Don't panic if your muscular build pushes you past the calculated maximum. Switch to a skinfold caliper test to get your actual body fat percentage.