What should a person of a given height actually weigh? There is no single perfect number, but clinicians have used rule-of-thumb formulas for decades to anchor the question. This ideal body weight calculator applies the Devine formula, the most widely taught estimate in hospitals and pharmacy dosing, and gives you a target weight in both pounds and kilograms along with a healthy range around it.
Enter your sex and height, and (optionally) your current weight, and the result card shows your ideal body weight, the +/-10% band most people regard as healthy, and how far you currently sit from that target. Smekys built this tool to make that number quick, transparent, and free to reuse.
How to Use
- Choose your Sex. The Devine formula starts from different base weights for men and women, so this choice directly changes the result.
- Enter your height in feet with the Height (feet) field (for example, 5 for five feet).
- Enter the remaining inches with Height (inches) as a number from 0 to 11. A height of 5 feet 10 inches, for instance, is feet = 5 and inches = 10.
- Optionally type your Current Weight in pounds. The calculator then shows the gap between where you are and the ideal target.
- Read the result card: the highlighted ideal weight in pounds, its kilogram equivalent, the healthy range about 10% below and above the target, and the difference from your current weight.
If your current weight is above the high end of the range, the gap tells you how many pounds you would need to move to reach the lower edge; if you are below the low end, the same number tells you how much weight to gain.
The Devine Formula
In 1974, B.J. Devine published a simple approximation that became the standard for drug dosing and nutritional planning. In its classic US form it is:
- Men: ideal body weight (lb) = 106 + 6 lb for every inch over 5 feet.
- Women: ideal body weight (lb) = 100 + 5 lb for every inch over 5 feet.
Five feet, or 60 inches, is the reference height. A man who is exactly 5 feet tall lands on 106 lb; a woman on the same height lands on 100 lb. Each additional inch adds 6 lb for men and 5 lb for women. The calculator then converts pounds to kilograms (1 lb = 0.45359 kg) and draws a healthy band from 90% to 110% of the ideal figure.
Worked example: a man who is 5 feet 10 inches is 10 inches over 5 feet. His ideal body weight is 106 + 6 x 10 = 166 lb, about 75.3 kg, with a healthy range of roughly 149 to 183 lb. A woman who is 5 feet 5 inches is 5 inches over 5 feet: 100 + 5 x 5 = 125 lb, about 56.7 kg, with a healthy range of 112 to 138 lb.
What the Number Does and Does Not Mean
The Devine number is a starting rule, not a health verdict. It ignores body frame size, muscle mass, bone density, and body composition. A lean athlete at 180 lb and 5 feet 10 inches can be healthier than a sedentary person at the formula's 166 lb, because muscle weighs more than fat. This is why the calculator shows a 20% wide healthy band rather than one exact target, and why it pairs naturally with a BMI or body-fat read rather than replacing them.
The formula is most useful as a practical anchor: for dosing, for setting a realistic first goal, and for giving you a ballpark range to discuss with a clinician. It is less reliable outside adult heights of roughly 5 to 6.5 feet, and it was never designed for children, pregnant people, or competitive athletes.
Examples
Example 1 — Average-height male. A man who is 5'10" with a current weight of 180 lb. The formula gives 166 lb ideal (75.3 kg) and a healthy band of 149.4 to 182.6 lb. His current 180 lb sits inside the band, so the gap shows +14 lb above ideal — a routine, non-urgent result.
Example 2 — Average-height female. A woman who is 5'5" weighing 130 lb. Ideal is 125 lb (56.7 kg), band 112.5 to 137.5 lb. Her gap is just +5 lb, comfortably within range.
Example 3 — Below the range. A 5'8" woman (68 inches) weighing 110 lb. Ideal = 100 + 5 x 8 = 140 lb, band 126 to 154 lb. Her gap is -30 lb, below the low edge — a signal to review nutrition with a professional rather than a prompt to diet.
Example 4 — Tall male. A 6'2" man (74 inches). Ideal = 106 + 6 x 14 = 190 lb (about 86.2 kg), band 171 to 209 lb. Enter 6 feet 2 inches in the form and the same figures appear on the card.
FAQ
How is ideal body weight calculated?
This calculator uses the Devine formula: for men, 106 lb plus 6 lb per inch over 5 feet; for women, 100 lb plus 5 lb per inch over 5 feet. Your total height in inches minus 60 gives the number of inches over 5 feet, which is multiplied by the per-inch factor and added to the base weight.
What is the ideal body weight for a 5'10" male?
A 5'10" man is 10 inches over 5 feet, so 106 + 6 x 10 = 166 lb, or about 75.3 kg, with a healthy range near 149 to 183 lb.
What is the ideal body weight for a 5'5" female?
A 5'5" woman is 5 inches over 5 feet, so 100 + 5 x 5 = 125 lb, or about 56.7 kg, with a healthy range near 112 to 138 lb.
Is the ideal body weight the same as a healthy weight?
Not exactly. Ideal body weight is one number; healthy weight is a range. This calculator shows a +/-10% band around the ideal figure. Many adults within that band are metabolically healthy, while people slightly outside it can also be healthy depending on body composition and activity.
How accurate is the Devine formula?
It is a clinical rule of thumb from 1974, still commonly used for drug dosing and nutrition planning. It is accurate as an estimate, not a diagnosis: it cannot account for frame size, muscle mass, age, or fat distribution. Treat its output as a discussion point with your doctor, not a verdict.
Should my goal weight be the ideal body weight exactly?
Usually the edge of the healthy band is a more forgiving and sustainable target. Landing within the 90%-110% range is a reasonable goal; chasing the exact ideal number is rarely necessary and can set an unrealistic bar.
How does ideal body weight differ from BMI?
BMI uses your weight divided by height squared and maps to broad categories (underweight, healthy, overweight, obese). Ideal body weight estimates a target weight directly from height and sex. They complement each other: use this calculator for a target in pounds, and a BMI calculator for how your current weight compares to population ranges.
Disclaimer
This ideal body weight calculator is provided for informational purposes only and is not medical advice. It applies the Devine formula, a historical rule of thumb, and its output is an estimate rather than a clinical recommendation. Body weight is influenced by frame size, muscle mass, health conditions, and many other factors this tool cannot measure. Always consult a qualified healthcare professional before making decisions about weight, diet, exercise, or medication dosing.