Ideal Weight Calculator
Calculate your ideal body weight using six scientifically validated formulas
Enter your height to calculate ideal weight using all formulas
Wrap your thumb and middle finger around your wrist to estimate frame size
Calculate Your Ideal Weight
Enter your height, gender, and frame size to see your ideal weight from multiple formulas.
How to Use the Ideal Weight Calculator
Select Your Gender
Choose male or female. Gender significantly affects ideal weight calculations because men and women have different body compositions, bone density, and muscle mass distributions.
Enter Your Height
Switch between imperial (feet and inches) or metric (centimeters) units, then enter your height. All six formulas use height as the primary variable for calculating ideal weight.
Choose Your Frame Size
Select small, medium, or large body frame. To determine your frame size, wrap your thumb and middle finger around your wrist: overlapping fingers mean small frame, touching means medium, and a gap means large frame.
Review Your Results
Compare ideal weight estimates from the Devine, Robinson, Miller, Hamwi, Peterson, and Lorentz formulas. Check the average ideal weight, healthy BMI range, and frame-adjusted range to get a complete picture of your target weight.
Frequently Asked Questions
What is the most accurate ideal weight formula?
No single formula is universally the most accurate because each was developed using different population samples and methodologies. The Devine formula (1974) is the most widely used in clinical practice and pharmaceutical dosing. The Robinson formula (1983) is often considered more accurate for the general population. The Miller formula (1983) tends to give slightly higher ideal weights, which some researchers believe is more realistic for modern populations. The Hamwi formula (1964) is the oldest and simplest. The Peterson formula (2016) is a modern BMI-based approach that uses a target BMI of 22 and is gender-neutral. The Lorentz formula is a popular European method with gender-specific calculations. Our calculator shows all six so you can see the range. The average of all six formulas typically provides the most balanced estimate for most people.
Why do the different formulas give different results?
Each formula was developed by different researchers using different study populations, time periods, and methodologies. The Devine formula was originally created for calculating medication dosages, not for general health guidance. Robinson and Miller refined the approach using larger datasets in 1983. Hamwi's formula from 1964 uses different coefficients based on earlier population data. The Peterson formula (2016) takes a fundamentally different approach by using a target BMI of 22, making it gender-neutral. The Lorentz formula, widely used in Europe, applies height-based subtractions with gender-specific divisors. These variations in research approach and reference populations explain why results differ by several pounds. The differences are typically small (5-15 pounds) and all results generally fall within the healthy BMI range. Using the average of all six provides a reasonable middle ground.
How does body frame size affect ideal weight?
Body frame size reflects your bone structure and skeletal width, which directly impacts how much you should weigh. People with larger frames have wider bones, broader shoulders, and larger joints, so they naturally carry more weight even at the same height as someone with a smaller frame. Generally, small-framed individuals should target the lower end of the ideal weight range (about 10% below average), while large-framed individuals should target the higher end (about 10% above average). You can estimate your frame size by wrapping your thumb and middle finger around your wrist. This simple test gives a reasonable approximation of your skeletal build.
Are ideal weight formulas accurate for athletes and muscular people?
Ideal weight formulas have significant limitations for athletes and muscular individuals. These formulas only use height and gender as inputs, so they cannot account for muscle mass, which weighs more than fat. A muscular person at 5'10" might weigh 200 pounds with low body fat and excellent health, but the formulas would suggest they are overweight. Similarly, the formulas do not account for age, ethnicity, or body composition. For athletes and active individuals, body fat percentage and waist-to-hip ratio are more useful metrics than ideal weight formulas. Consider using our BMI calculator alongside this tool for additional context.
What is a healthy BMI range and how does it relate to ideal weight?
A healthy BMI (Body Mass Index) falls between 18.5 and 24.9. BMI is calculated by dividing your weight in kilograms by your height in meters squared. Our calculator converts this into a weight range for your specific height, showing you the minimum and maximum weight that would give you a healthy BMI. This BMI-based range is typically wider than the individual formula results and is recognized by the World Health Organization as a standard health metric. Most ideal weight formula results fall within the healthy BMI range. If a formula result falls outside this range, the BMI range may provide a more medically relevant target to aim for.