AtlasCalcsUtility Calculation Suite
2026-09-15 7 min

Robinson Ideal Weight Calculator

Robinson (1983) ideal weight for your height and sex — with Devine, Miller, and Hamwi siblings, BMI equivalent, and personal gap.

Calculator

Units & Profile

Units
Gender
Male Female

Height & Weight (Metric)

Height cm
Current Weight kg
Results update automatically
Results update live as you type
Status:Robinson 71.1 kgBMI ≈ 22.5-2.0 kg vs Devine

Robinson Summary

Robinson Ideal71.1 kg (156.9 lbs)
BMI Equivalent22.5
SiblingsD 73.2 kg · M 70.4 kg · H 75.2 kg
Your Gap+3.9 kg (8.5 lbs)

Results

Normal

Robinson Ideal

71.1 kg (156.9 lbs)

52 + 1.9/in over 5 ft

BMI Equivalent

22.5

Where Robinson lands on the BMI scale

vs Devine

-2.0 kg

Devine reads 73.2 kg (161.3 lbs) here

Your Gap

+3.9 kg (8.5 lbs)

3.9 kg over Robinson — compare against the BMI band before acting.

Robinson refines interpretation; Devine still rules dosing references. Treat every formula as an anchor and judge residence by BMI band plus composition.

Visualizations

Sibling Formulas (kg)

71.1 kgRobinson
73.2 kgDevine
70.4 kgMiller
75.2 kgHamwi

You vs Robinson

You75 kg

Formula

Higher intercept, gentler climb: Robinson’s 1983 refit tracks actuarial ideals better than Devine above ~5 ft 8 in.

Robinson M: 52 + 1.9(in−60) · F: 49 + 1.7(in−60)

Alternative Form

Siblings — Devine 2.3 · Miller 1.41/1.36 · Hamwi 2.7/2.2

Variables

SymbolNameUnitDescription
inHeightinchesTotal standing height
baseFive-foot basekg52 men / 49 women
slopePer-inch ratekg/in1.9 men / 1.7 women
ΔDevineDevine gapkgRobinson − Devine at your height

Explanation

Refitting Devine’s line to newer height-weight tables flattened the slope and lifted the base — the regression’s verdict that tall ideals had run too hot.

Derivation

178 cm male (70.1 in): 52 + 1.9 × 10.1 = 71.1 kg vs Devine 73.2 — Robinson 2.1 kg lighter.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Convert height to total inches.

in = cm ÷ 2.54
Height:178.0 cm
Intermediate: 178.0 ÷ 2.54
Result: 70.1 inches (10.1 over 5 ft)
Step 2

Apply the Robinson equation.

R = 52 + 1.9 × (in − 60)
Inches:70.1
Gender:male
Intermediate: 52 + 1.9 × 10.1
Result: Robinson = 71.1 kg (156.9 lbs)
Step 3

Run the siblings for context.

Devine 2.3 · Miller 1.41/1.36 · Hamwi 2.7/2.2
Inches:70.1
Intermediate: 73.2 · 70.4 · 75.2
Result: Robinson sits -2.0 kg vs Devine
Step 4

Translate Robinson to BMI.

BMI = R ÷ h²
Robinson:71.1 kg
Height:1.78 m
Intermediate: 71.1 ÷ 3.1684
Result: BMI ≈ 22.5
Step 5

Gap your weight against it.

Gap = W − Robinson
Weight:75.0 kg
Robinson:71.1 kg
Intermediate: 75.0 − 71.1
Result: 3.9 kg over Robinson — compare against the BMI band before acting.
Final Answer
71.1 kg (156.9 lbs)

Worked Examples

See how the calculator works with different scenarios.

Scenario

A man, 178 cm, 75 kg.

Inputs

Height:178 cm (70.1 in)
Weight:75 kg

Calculation

R = 52 + 1.9 × 10.1 = 71.1 kg BMI ≈ 22.5

Result

Robinson 71.1 kg · +3.9 over

Interpretation

Modestly over the line at a healthy BMI — habits overhauls unnecessary; a gentle recomposition suffices.

Understanding Your Result

Your Result: Robinson Ideal: 71.1 kg (156.9 lbs)

Typical range: Usually BMI 20–23; 1–4 kg under Devine above 5 ft 8 in; near-identical below 5 ft 4 in.

What This Means

Your Robinson number is the 1983 consensus ideal for your height and sex — flatter and fairer than Devine, especially tall.

Why It Matters

It anchors expectations where Devine overshoots: tall dieters chasing Devine fight phantom kilograms Robinson forgives.

Professional Interpretation

Cite Robinson alongside Devine in counseling; dose by Devine/monograph in clinic. The pair brackets honest uncertainty.

Recommendations

  • •Use Robinson for tall-anchor realism
  • •Average with siblings for planning
  • •Judge residence by BMI band
  • •Confirm athletes with body fat
  • •Recheck only with height changes

Educational Content

Introduction

In 1983 Robinson asked whether Devine’s line still fit the data — and redrew it flatter. This page is that redrawn line, live.

Concept Explanation

Base (52/49) + gentle slope (1.9/1.7) × inches over five feet. Siblings shown for context; BMI equivalent for modern judgment.

Applications

▸Realistic tall-height anchors
▸Nutrition screening references
▸Bariatric excess-weight math
▸Counseling against Devine-only plans
▸Teaching formula literacy

Benefits

  • •Tall-fair recalibration
  • •Sibling context built in
  • •BMI translation included
  • •Gap computed instantly

Limitations

  • •Dosing standard remains Devine
  • •No composition awareness
  • •Adult validation only

Best Practices

  • •Barefoot half-cm height
  • •Pair with band and body fat
  • •Cite the cluster, not the line
  • •Revisit with big weight moves

Common Misconceptions

Myth: Newer means Robinson replaces Devine.
Truth: It refines interpretation; dosing references still cite Devine. Different jobs, both valid.
Myth: Lower ideals are always better.
Truth: Robinson runs lower tall — that is accuracy, not aspiration. Chasing the lowest line is still disordered thinking.
Myth: One formula suffices now.
Truth: 1983 produced two independent flatter lines (Robinson + Miller). Their agreement matters more than either alone.

Practical Tips

  • •Tall? Start with Robinson
  • •Cluster, never solo
  • •Band judges, lines anchor
  • •Half-cm height care
  • •Athletes: fat-check verdicts
  • •Anchors rarely expire

Common Mistakes

Dosing off Robinson
Monographs cite Devine. Robinson informs counseling; pharmacy decides dosing.
Chasing the lowest line
Miller often undercuts Robinson — racing to the bottom is pathology, not precision.
Ignoring the band
Formula gaps of 2 kg mean nothing against 20 kg bands. Judge residence first.
Shoes-on height
Two phantom centimeters add ~3 kg of phantom ideal. Barefoot always.
Short-stature overanalysis
Lines converge near 5 ft — any formula works there. Save analysis for tall cases.

Assumptions

This calculator makes the following assumptions to provide estimates:

Robinson 1983 constants: Bases 52/49, slopes 1.9/1.7 from original publication.
Sibling context constants: Devine/Miller/Hamwi standard constants.
Adult statures: Validated roughly 140–220 cm.

Limitations

Be aware of these limitations when using this calculator:

Not the dosing standard: Clinical dosing references cite Devine.
Composition-blind: Muscle vs fat invisible.
Static anchor: Height-fixed; gaps need fresh weights.

Frequently Asked Questions

Answers to common questions about this calculator.

What is the Robinson formula?
The 1983 J.D. Robinson recalibration of Devine: men 52 + 1.9 kg per inch over 5 ft; women 49 + 1.7 kg per inch. Gentler slopes than Devine’s 2.3 for both sexes.
Why was Robinson created?
Devine’s steep 2.3 slope overestimated tall ideals versus actuarial data. Robinson (with Miller, same year) refit the line — higher base, flatter climb — for better real-world agreement.
How does Robinson differ from Devine?
At 5 ft they differ by the base gap (52 vs 50 men); each inch above shrinks Robinson’s relative position by 0.4 kg (men) or 0.6 kg (women). Tall Robinson ideals run notably lower.
Work an example?
A 5 ft 10 in man: Robinson = 52 + 1.9 × 10 = 71 kg; Devine = 50 + 2.3 × 10 = 73 kg. A 5 ft 5 in woman: Robinson = 49 + 1.7 × 5 = 57.5 kg.
When is Robinson the best choice?
For mid-to-tall adults where Devine feels heavy, and whenever citing the 1983 literature pair. For dosing, Devine remains the cited standard — Robinson informs, rarely prescribes.
Is Robinson better for women?
Its 1.7 slope (vs 2.3) tracks female actuarial data more closely above 5 ft 5 in. Short women see little difference; tall women see several kilograms.
What BMI does Robinson imply?
Typically 20–23 across average heights — comfortably mid-band. Very tall Robinson ideals can dip toward BMI 20, where the band (not the formula) should adjudicate.
Why show Devine, Miller, and Hamwi too?
No formula owns truth; the siblings expose Robinson’s position (usually second-lowest for the tall, near-top for the short). Context prevents false precision.
Does Robinson handle frames?
Not explicitly — apply Hamwi’s ±10% convention if needed: small frames take ~10% under, large frames ~10% over the Robinson number.
Can Robinson guide weight loss?
As one anchor among several: pair with the BMI band and body-fat data. Single-formula dieting ignores composition the way all height math does.
What about heights under 5 feet?
Extrapolates linearly (subtract per inch below 60 in) with thinner validation. Short adults should weight the BMI band above any single line.
Is Robinson used in medicine?
Occasionally in nutrition screening and bariatric excess-weight math, but Devine dominates dosing references. Know Robinson for literacy; dose by monograph.
How precise should height be?
Half-centimeter barefoot: each inch moves Robinson 1.9/1.7 kg, so a 2 cm shoe error shifts the ideal ~1.5 kg — noise that matters at boundaries.
Why 1983 matters?
Robinson and Miller independently converged on flatter slopes the same year — strong signal Devine ran steep. Their agreement is the real finding; either line alone is secondary.

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Glossary

Technical terms used in mortgage calculations explained in plain language.

Robinson equation
1983 IBW refit: 52+1.9 (M), 49+1.7 (F) per inch over 5 ft.
Recalibration
Refitting Devine’s line to newer height-weight data.
Slope gap
0.4/0.6 kg-per-inch flattening vs Devine.
Sibling context
Devine/Miller/Hamwi shown alongside.
BMI equivalent
Robinson translated to the BMI scale.
Tall-fair
Reduced overshoot above ~5 ft 8 in.
Convergence
Lines agreeing near five feet.
Excess weight
Actual minus ideal (bariatric usage).

Authoritative References

Trusted sources and standards referenced by this calculator.

Applicable Standards

Robinson et al. (1983) IBW equationsDevine (1974) comparison standard

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Page Information

Last Updated:

2026-09-15

Version:

2.0.0

License:

Free to use for educational and professional purposes.