How much should I weigh? (The 4 Formulas)
Doctors and pharmacists have developed several equations over the decades, mostly to calculate drug dosages (since some drugs are dosed based on "lean" weight rather than total weight).
| Formula | Year | Best For... |
|---|---|---|
| Devine | 1974 | The medical standard & most widely used. |
| Robinson | 1983 | Refinement of Devine via new data. |
| Miller | 1983 | Often yields lower, "leaner" estimates. |
| Hamwi | 1964 | The easy "Rule of Thumb" for quick math. |
Ideal Weight vs. BMI
BMI is a broad range (e.g. 18.5 - 24.9), whereas Ideal Weight is a specific target. A healthy BMI gives you more wiggle room for muscle mass and body type.
Check your status with our BMI Calculator →Reaching Your Goal
If you are significantly above your ideal range, the key is to create a sustainable plan. Don't crash diet.
Plan your weight loss with our Deficit Calculator →Frequently Asked Questions
Why does the Miller formula give a lower number?
The Miller formula (1983) derives its coefficients from a slightly different dataset. It tends to result in lower estimates compared to Devine and is often cited as being more in line with modern "slender" aesthetic preferences, whereas Devine is strictly for pharmacology.
I am 5'4 female, what is my ideal weight?
Based on the Robinson formula, your ideal weight would be approximately 119 lbs (54 kg). However, a healthy BMI range (18.5-24.9) allows for a weight between 110 lbs and 145 lbs depending on your muscle mass and frame size.
Does age affect ideal weight?
Technically, the IBW formulas do not include age as a variable. However, medical research suggests that older adults (65+) may benefit from being slightly heavier (higher end of BMI) to provide a nutritional reserve against illness. See our Body Fat Calculator for a better health metric than simple weight.
Tools & Data Verified by the EverydayCalculators Medical Research Team.
Last updated: December 2026.