Discover Your
Ideal Weight
Set a realistic, scientifically-backed target. We calculate your ideal body weight using the Devine, Robinson, and Miller formulas, giving you a clear goal for your fitness journey.
Clinical Grade: These formulas are the exact same ones used by doctors, dietitians, and pharmacists to determine healthy dosages and target nutritional baselines based on gender and height.
Understanding The Formulas
Why are there multiple different “ideal” weights?
Devine Formula
Originally invented in 1974 strictly for calculating drug dosages in medical settings, the Devine formula is now the most widely used standard on the internet for calculating Ideal Body Weight (IBW).
Robinson Formula
Created in 1983 by J.D. Robinson as a modification to the Devine formula. Robinson felt the Devine formula didn’t adequately account for variations in taller individuals, altering the calculations slightly.
Miller Formula
Also proposed in 1983, Dr. Miller’s formula is another variation. It tends to generate slightly lower ideal weight numbers for taller individuals compared to Devine and Robinson.
What Does “Ideal Weight” Actually Mean?
The truth is, there is no single magical number that defines perfect health. “Ideal Body Weight” is a mathematical guideline, not a biological mandate.
When people search for their ideal weight, they are usually looking for an aesthetic goal or a reassurance of health. Medically speaking, “Ideal Body Weight” (IBW) was primarily developed for calculating the clearance rates of certain drugs in patients. Because fat tissue and muscle tissue absorb medication differently, doctors needed a standardized formula based on height to estimate lean body mass.
The Problem with Formulas
The Devine, Robinson, and Miller formulas are excellent starting points, but they have distinct limitations. The most glaring issue is that they do not account for frame size or muscle mass.
Imagine two women who are both 5’5″ (165 cm). One has a naturally small bone structure and does not exercise, while the other has a broad skeletal frame and is a competitive weightlifter. The formulas will output the exact same “ideal weight” for both, despite their vastly different biological realities. If the weightlifter tried to reach her calculated “ideal” weight, she would likely have to lose healthy, active muscle mass.
Why We Include the BMI Range
Because specific formulas can be too rigid, we highlight the Healthy BMI Range as your primary target. The World Health Organization defines a healthy BMI as being between 18.5 and 24.9. This creates a much wider, more forgiving “Healthy Weight Range.” As long as your weight falls comfortably inside this zone, and your Body Fat Percentage is normal, you are considered to be at an ideal weight for your height.
How to Use This Information
If you are starting a weight loss or weight gain journey, use the specific formula averages (Devine/Robinson) as a long-term goal post. However, do not obsess over hitting that number perfectly. Your goal should be body recomposition: reducing fat mass, increasing lean muscle, and ensuring your blood markers (cholesterol, blood pressure, insulin) are healthy.
Ideal Weight FAQs
Common questions about healthy target weights.
Many people find the Devine or Robinson results to be lower than they expected. This is because these formulas aim for a very lean baseline. Modern averages are much higher than historical “ideal” averages. If the number seems unattainable, focus on hitting the higher end of the Healthy BMI range instead.
Using both in combination is best. BMI gives you a safe “zone” (e.g., between 60kg and 75kg for your height), while the IBW formulas give you a specific target point inside that zone to aim for.
No. These formulas (and adult BMI ranges) are exclusively calibrated for adults aged 18 and older. Children’s ideal weights are determined by pediatric growth percentile charts.
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