The Ideal Weight Calculator computes ideal body weight (IBW) ranges based on height, gender, and age. Currently, there persist several popular formulas, and our calculator provides their results for side-to-side comparisons.
How Much Should I Weigh?
Most people have at some point tried to lose weight or known someone who has. This is largely driven by the perception of an "ideal" body weight (IBW), which is frequently promoted through social media, television, movies, and magazines.
In reality, IBW was originally introduced to **estimate drug dosages for medical use** (since the metabolism of certain drugs is based more on IBW than total body weight) and to classify athletes in weight-restricted sports. It is not an exact science. Lean muscle mass and fat percentages are not considered, meaning a highly fit, muscular athlete can be classified as "overweight" by standard formulas.
Major Factors Affecting Ideal Weight
Age
Growth stops around ages 14-17. After age 70, humans naturally lose 1.5–2 inches of height, while muscle mass decreases and body fat accumulates more easily.
Gender
Males generally weigh more than females because they have higher muscle mass (which is denser than fat) and higher bone density.
Height
Height is the primary determinant. Taller people have more muscle mass and skeletal weight. A male is typically 10–20% heavier than a female of the same height.
Body Frame Size (Wrist Circumference)
Your skeletal structure affects your weight. Frame size is determined by measuring wrist circumference relative to height:
| Height | Small Boned | Medium Boned | Large Boned |
|---|---|---|---|
| Under 5'2" | < 5.5" | 5.5" – 5.75" | > 5.75" |
| 5'2" to 5'5" | < 6.0" | 6.0" – 6.25" | > 6.25" |
| Over 5'5" | < 6.25" | 6.25" – 6.5" | > 6.5" |
| Frame Size | Wrist Circumference |
|---|---|
| Small Boned | 5.5" to 6.5" |
| Medium Boned | 6.5" to 7.5" |
| Large Boned | > 7.5" |
Formulas for Finding the Ideal Weight
All formulas are based on a base weight given a height of 5 feet, plus a set increment per inch over 5 feet:
• Male: 48.0 kg + 2.7 kg per inch over 5 feet
• Female: 45.5 kg + 2.2 kg per inch over 5 feet
• Male: 50.0 kg + 2.3 kg per inch over 5 feet
• Female: 45.5 kg + 2.3 kg per inch over 5 feet
• Male: 52.0 kg + 1.9 kg per inch over 5 feet
• Female: 49.0 kg + 1.7 kg per inch over 5 feet
• Male: 56.2 kg + 1.41 kg per inch over 5 feet
• Female: 53.1 kg + 1.36 kg per inch over 5 feet
Healthy BMI Range
The World Health Organization (WHO) recommended healthy BMI range is **18.5 – 24.9** for both males and females. For children and teenagers, the CDC recommends maintaining a BMI between the **5th and 85th percentiles** based on age-specific growth charts.
How it Works & Formula
Multiple formulas are provided: Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964), plus the healthy BMI range of 18.5–24.9.
Practical Examples
A 5'10" male has ideal weights ranging from 155–165 lbs depending on formula, with a healthy BMI range of 129–174 lbs.
A 5'5" female has ideal weights ranging from 122–138 lbs depending on formula, with a healthy BMI range of 111–150 lbs.
Frequently Asked Questions
How is ideal weight calculated?
Multiple formulas estimate IBW using height and gender. Popular ones include Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964). Each uses a base weight at 5 feet and adds weight per inch over 5 feet.
Is the healthy BMI range the same as ideal weight?
Not exactly. BMI-based ranges (18.5–24.9) give a healthy weight range, while formula-based ideal weights target a single optimal value. Both are useful reference points.
Do these formulas account for muscle mass?
No. These formulas use height and gender only. Athletes or muscular individuals may weigh more than the "ideal" and still be healthy. Body fat percentage is a better indicator for them.