Ideal Weight by Frame Size Calculator
Estimate a healthy body-weight target from height, sex and frame size using the Hamwi method, with a small-, medium- and large-frame range.
How it works
Men: 48 kg + 2.7 kg per inch over 5 ft · Women: 45.5 kg + 2.2 kg per inch over 5 ft · Small frame ×0.9 · Large frame ×1.1
The Hamwi method gives a quick height-based ideal weight, then adjusts ±10% for frame size, recognising that a broad-shouldered, big-boned person can healthily carry more than a slight one of the same height. Frame is usually judged from wrist circumference relative to height or the space between the two bones at your elbow. Like all height-only formulas it ignores muscle mass, so a lean athlete may sit above the range without excess fat.
Worked example
A 175 cm man stands 8.9 inches over 5 ft, so the medium-frame weight is 48 + 2.7 × 8.9 = 72.0 kg. A small frame trims 10% to 64.8 kg and a large frame adds 10% to 79.2 kg.
Frequently asked questions
How do I know my frame size?
A common test: wrap your thumb and index finger around the opposite wrist. If they overlap you likely have a small frame, just touching is medium, and not meeting is large. Wrist circumference relative to height is the more precise version.
Is ideal weight the same as a healthy weight?
Not exactly. These formulas estimate a mid-point, but a healthy weight is a range. Body composition, fitness and health markers matter more than hitting one number.
Why adjust for frame at all?
Bone structure and joint width vary between people of the same height, so a fixed target over- or under-shoots for those at the extremes. The ±10% band accounts for that spread.
Related calculators
Educational estimate using standard formulas and population averages — not medical advice. Talk to a qualified clinician before making decisions about diet, training, or pregnancy.