Ideal Weight Calculator
Estimate your ideal body weight with the Devine formula and see your healthy BMI weight range, adjusted for frame size.
Ideal Weight Calculator — input your values
What does this health calculator do?
This ideal weight calculator estimates your target weight using the Devine formula, which assigns 50 kg for men or 45.5 kg for women at 5 feet tall, then adds 2.3 kg for every inch above that. An optional frame-size adjustment shifts the result by 10% for small or large frames.
It also shows the full healthy BMI range (18.5–24.9) for your height, so you can see both the formula-based figure and the evidence-based range your weight should comfortably fall within.
Ideal weight is a statistical reference, not a measure of health on its own. Body composition, fitness and medical history matter more than any single target — use the numbers as context, not a mandate.
Formula and variables
The Devine formula was developed for estimating drug dosing weights and is one of several widely used ideal weight formulas.
| Symbol | Meaning |
|---|---|
| height_in | Height in inches |
| frame | Frame adjustment: × 0.9 (small), × 1 (medium), × 1.1 (large) |
Worked example
A woman, 5 ft 7 in (67 in), medium frame.
- Base = 45.5 + 2.3 × (67 − 60) = 45.5 + 16.1 = 61.6 kg.
- Medium frame: no adjustment, ideal ≈ 61.6 kg.
- Healthy BMI range: 18.5 × 1.7² to 24.9 × 1.7² = 53.5 – 72.0 kg.
Answer: Ideal weight ≈ 61.6 kg, with a healthy range of about 53.5–72 kg.
Tips and common mistakes
Tips
- Estimate your frame by wrapping thumb and middle finger around your opposite wrist — if they overlap, you're likely small-boned.
- If you carry significant muscle, favor the healthy BMI range rather than the formula number.
- Aim to stay within the healthy range rather than hitting an exact formula value.
- Check your waist circumference too — it captures fat distribution that weight alone misses.
Common mistakes to avoid
- Treating the formula result as a hard target instead of a range.
- Choosing a large frame to justify a heavier weight — frame adjustment should be estimated honestly.
- Ignoring the healthy BMI range, which is the better-validated measure for most people.
Ideal Weight Calculator — frequently asked questions
What is the Devine formula?
It estimates ideal body weight as 50 kg for men or 45.5 kg for women at 5 feet tall, plus 2.3 kg per additional inch of height.
Is ideal weight the same as healthy weight?
Not exactly. Ideal weight comes from dosing formulas; healthy weight is the range associated with the lowest health risks, usually defined by a BMI of 18.5 to 24.9.
Does frame size really matter?
Research is mixed, but bone structure does influence what weight looks natural for you. The optional 10% adjustment is a reasonable accommodation for that.
Why does the calculator show a range?
Because no single weight is right for everyone. The healthy BMI range captures normal variation in build, muscle and bone density.
What if I weigh more than the ideal weight but lift weights?
Muscle is dense, so athletic people often exceed formula weights while staying lean. Body composition measurements are more informative in that case.
How do I measure my height correctly?
Stand barefoot against a wall with heels together and look straight ahead. Use a flat object on top of your head to mark the height, ideally first thing in the morning.