📌 These are estimates. Ideal weight varies by body frame, muscle mass, and individual factors.

About the Ideal Weight Calculator

What should you weigh? The answer isn't as simple as a single number — it depends on your height, sex, frame size, age, and body composition goals. Our Ideal Weight Calculator runs four clinically established formulas simultaneously so you can see a range of evidence-based targets, rather than chasing a single arbitrary number.

Understanding your ideal weight range helps you set realistic fitness goals, evaluate weight loss progress in context, and have informed conversations with your healthcare provider about weight management.

How It Works

Enter your height, sex, and optionally your frame size. The calculator applies four established medical formulas — Devine, Robinson, Miller, and Hamwi — to produce a range of ideal body weight (IBW) estimates. It also shows the corresponding BMI for each result.

Formula / Key Reference

Devine Formula:

Men: IBW = 50 kg + 2.3 kg per inch over 5 feet

Women: IBW = 45.5 kg + 2.3 kg per inch over 5 feet

Hamwi Formula:

Men: IBW = 48 kg + 2.7 kg per inch over 5 feet

Women: IBW = 45.5 kg + 2.2 kg per inch over 5 feet

Robinson Formula:

Men: IBW = 52 kg + 1.9 kg per inch over 5 feet

Women: IBW = 49 kg + 1.7 kg per inch over 5 feet

Real-World Example

Woman, 5'6" tall (168 cm)

Devine: 45.5 + 2.3 × 6 = 45.5 + 13.8 = 59.3 kg (130.7 lbs)
Hamwi: 45.5 + 2.2 × 6 = 45.5 + 13.2 = 58.7 kg (129.4 lbs)
Robinson: 49 + 1.7 × 6 = 49 + 10.2 = 59.2 kg (130.5 lbs)
Miller: 53.1 + 1.36 × 6 = 53.1 + 8.16 = 61.3 kg (135.1 lbs)

Ideal weight range: approximately 129–135 lbs

This range corresponds to a BMI of approximately 20.9–21.8 — well within the healthy normal range. A woman who weighs 150 lbs at this height is not dramatically overweight (BMI 24.2), but has about 15–20 lbs of room before hitting the BMI overweight threshold.

Common Uses

  • Setting a realistic, medically grounded weight loss goal
  • Evaluating current weight relative to clinical ideal ranges
  • Supporting clinical dosage calculations that use IBW (many medications are dosed per IBW)
  • Setting healthy benchmarks in fitness and wellness programs
  • Understanding how much weight loss changes your BMI and health risk profile

Frequently Asked Questions

Is there one ****'****correct****'**** ideal weight? ▼
No. All ideal weight formulas are statistical averages for populations — they don't account for muscle mass, bone density, ethnicity, or individual metabolism. The four formulas often differ by 5–10 lbs. Use the range as a guide, not an absolute target, and discuss your individual goal with a doctor or dietitian.
Do these formulas work for everyone? ▼
The Devine formula was originally developed for pharmacological dosing and is most accurate for adults of average height (5'3"–5'11"). It may underestimate ideal weight for taller individuals and overestimate for shorter ones. Athletes with high muscle mass will typically weigh more than their IBW without any health concern.
What is small, medium, and large frame? ▼
Frame size is estimated by wrist circumference relative to height, or by measuring the elbow breadth. A larger frame means a heavier bone structure, which naturally adds body weight independent of fat. Some practitioners add ±10% to IBW for small and large frames respectively.