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Health & Fitnessbody composition

Ideal Body Weight Calculator

Healthy weight as a range rather than a single number. The Devine and Hamwi formulas were built for drug dosing, not for setting personal targets, and they return one number where a range is the honest answer.

Also called: healthy weight calculator, ideal body weight.

cm
Sex
Frame size
kg
Healthy weight range
54.7 to 74 kg

54.7 to 74 kg on the BMI range of 18.5 to 25 for your height. The older Devine formula gives 67.7 kg and Hamwi 68.8 kg. You are currently 78 kg, 4 kg above the range. Devine and Hamwi were published for drug dosing in 1974 and 1964. Neither was derived from health outcomes.

Lower end of the healthy range
54.7
Upper end of the healthy range
74
Devine formula
67.7
Hamwi formula
68.8
Current BMI
26.37
Distance to the range
4
Where you sit
4 kg above the range
On the formulas
Devine and Hamwi were published for drug dosing in 1974 and 1964. Neither was derived from health outcomes.
How this is calculated

For reference only. Verify against your clinical protocol before acting on this number.

Method and background

This is what the calculation gives for the numbers you entered. It is an estimate, not advice, and it knows nothing about your situation beyond those numbers. Rules for United States change on a published schedule; the effective date is shown on every rule-based tool.

How this is calculated

The BMI range of 18.5 to 25 converted to weight for your height gives a band, which is what the evidence supports. The single-value formulas shown alongside have a specific history: Devine was published in 1974 to calculate drug doses and Hamwi in 1964 for insulin dosing in diabetes. Neither was derived from health outcomes, and both return a point value that reads like a target it was never meant to be. Frame size adjusts the range slightly and is itself a rough judgement.

the BMI range gives a band, where the older single-value formulas give a point that was never meant as a target
h
Height in metres

Full derivation: BMI, and where the 703 comes from

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

a 172 cm adult

Height
172 cm
Sex
Male
Frame size
Medium
Current weight
78 kg

Healthy weight range54.7 to 74 kg

18.5 and 25 times 1.72 squared

Open this example

a small frame narrows the range

Height
172 cm
Sex
Male
Frame size
Small
Current weight
78 kg

Healthy weight range52 to 70.3 kg

boundary: a 5 percent adjustment

Open this example

Method and limits

What it assumes

  • Adults. Children use growth percentiles rather than BMI thresholds.

What it deliberately does not model

  • BMI does not distinguish muscle from fat, so it misclassifies athletes and the very sedentary alike.
  • The thresholds were derived largely from European populations and fit poorly elsewhere.
  • Body composition and waist measurement predict health outcomes better than weight alone.

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

Why is there a range rather than one number?
Because the evidence supports a range. The single-value formulas came from drug dosing research in the sixties and seventies and were never intended as personal targets.
Is BMI reliable?
As a population screening tool, reasonably. For an individual it cannot distinguish muscle from fat, which is why waist measurement and body composition are more informative.