Dress Size Calculator
Estimate a US dress size reference from bust, waist and hip measurements.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
This is a simple US reference model, not a brand size chart. It estimates a number from bust, waist and hip measurements and returns the largest of the three estimates. Compare the result with the garment maker’s chart, especially when measurements fall across different sizes.
Worked example
calculated with the default values below
Bust (selected unit) 36 · Waist (selected unit) 29 · Hip (selected unit) 39 · Measurement unit Inches Size by bust 5 · Size by waist 5 · Size by hip 5 · Largest size estimate 5 · Letter size S
General background references
Disclaimer
These calculators give general estimates. Sizing, pricing, availability and standards vary by brand, retailer and country, so treat the output as a starting point and confirm it against the seller's or authority's own figures.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
nW = max(0, round((W − 24) ÷ 1.5) + 2); nH = max(0, round((H − 34) ÷ 1.5) + 2); nB = max(0, round((B − 31) ÷ 1.5) + 2); N = max(nB, nW, nH)
- B
- bust, inches
- W
- waist, inches
- H
- hip, inches
- nB
- size by bust
- nW
- size by waist
- nH
- size by hip
- N
- largest estimated US size
Convert bust, waist and hip to inches. size estimate = max(0, round((bust−31)/1.5)+2, round((waist−24)/1.5)+2, round((hip−34)/1.5)+2). The fixed baselines are a simplified US reference model, not a brand chart.
Frequently asked questions
How does the dress-size estimate choose a result?
It estimates a US number separately from bust, waist and hip measurements using fixed reference formulas, then shows the largest estimate. These formulas are a simple model rather than a particular brand’s chart. Compare all measurements with the garment maker’s guide.