Ideal Body Weight Calculator (Robinson Formula)

Calculate your ideal body weight using the Robinson formula (1983). A refined clinical IBW equation that gives slightly higher estimates than Devine for most heights.

About the Ideal Body Weight Calculator (Robinson Formula)

The Robinson formula is a historical ideal body weight equation that is still reproduced in clinical references. It uses a higher base weight and a smaller per-inch increment than Devine, so the comparison depends on height.

The formula is best read as one reference estimate rather than a universal target or a direct measure of health.

Why Use This Ideal Body Weight Calculator (Robinson Formula)?

Robinson is one of several historical IBW equations. It can be helpful when comparing reference weights, but it should not be treated as more accurate simply because it is more recent than some alternatives.

How to Use This Calculator

  1. Select your sex.
  2. Enter your height in feet/inches or centimeters.
  3. Optionally enter actual weight for comparison.
  4. View your Robinson IBW and healthy range.
  5. Compare with Devine, Miller, and Hamwi estimates.

Formula

Men: IBW = 52.0 + 1.9 × (height in inches − 60) Women: IBW = 49.0 + 1.7 × (height in inches − 60) Result in kg. Healthy range: IBW ± 10%

Example Calculation

Result: IBW: 71.0 kg (156 lbs) | Range: 63.9–78.1 kg

For a male at 5'10" (70 inches): IBW = 52.0 + 1.9 × (70 − 60) = 52.0 + 19.0 = 71.0 kg (156 lbs). This is 2 kg less than Devine's 73.0 kg because Robinson's per-inch increment (1.9 kg) is lower than Devine's (2.3 kg).

Tips & Best Practices

Robinson vs. Devine at Different Heights

Robinson and Devine can differ by a few kilograms depending on height. That is expected, because the equations were developed from different historical assumptions.

Using IBW in Practice

When comparing multiple IBW formulas, the useful output is the range rather than a single "correct" value. If the formulas diverge significantly, that is a cue to interpret the estimate cautiously.

Sources & Methodology

Last updated:

Methodology

This calculator applies the Robinson ideal-body-weight equation and shows it as a historical reference estimate. The page compares Robinson with nearby formulas so the user can see how historical equations vary, rather than implying that one exact weight can be derived from height alone.

Because Robinson is a simple historical equation, the result should be read as a rough reference, not as a validated health target.

Sources

Frequently Asked Questions

How does Robinson differ from Devine?

Robinson is commonly reproduced as a historical ideal-body-weight equation with a higher base and smaller height increment than Devine. That makes it useful for comparison, but not for identifying one correct weight.

Is Robinson more accurate than Devine?

Neither formula is definitively more accurate. Robinson is best understood as one historical estimate among several.

When was the Robinson formula developed?

Robinson is usually cited as one of the standard historical ideal-body-weight equations alongside Devine, Miller, and Hamwi.

Which IBW formula should I use?

No single formula is correct for all people. Comparing several equations is usually more informative than relying on one number.

Is IBW the same as healthy weight?

BMI and IBW answer different questions. BMI classifies weight-for-height ranges, while IBW formulas produce reference weights.

Do these formulas work for children or elderly?

No. These formulas were developed for adults; children should use age- and sex-specific growth references.

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