Waist-to-Height Ratio Calculator

Enter waist circumference, height, and optional age to calculate WHtR, view a continuous adult reference band, and compare waist size with half your height.

Enter your measurements

Measurement unit
cm
Measure horizontally at the end of a normal breath, with the tape snug but not tight.
cm
Measure without shoes and use the same unit as waist circumference.
Optional. Age does not change the formula; it helps flag when adult references should not be used.

An example is loaded. Edit an input to update the result.

Calculated locally in your browser; measurements are not uploaded.

Instant result

Waist-to-height ratio (WHtR)0.50Rising adult reference band
  • Below 0.40 · Below the usual adult reference range
  • 0.40 to below 0.50 · Lower adult reference band
  • 0.50 to below 0.60 · Rising adult reference band
  • 0.60 or higher · Higher adult reference band
Adult reference band
Rising adult reference band
Waist at half your height
85.0 cm
Formula
85 ÷ 170 = 0.50

This result is at or above the half-height reference point. It is a screening signal, not a diagnosis or individual treatment target.

How to understand the result

Use a continuous risk band

WHtR changes continuously. The 0.50 point is a practical adult screening reference, not a universal line separating healthy from unhealthy.

What to do next

Repeat the measurement at the same site. If the value concerns you or you have symptoms or medical conditions, discuss it with a qualified healthcare professional.

How to use the waist-to-height ratio calculator

  1. Choose one unitChoose centimetres or inches. Waist circumference and height must use the same unit.
  2. Enter waist, height, and optional ageMeasure waist at the end of a normal breath and height without shoes. Age only controls whether adult reference bands are shown.
  3. Review the ratio and contextRead the unrounded reference band, the waist value at half your height, measurement limits, and suggested next steps.

Formula, assumptions, and limits

Formula and calculation basis

WHtR = waist circumference ÷ height. Waist and height must use the same unit, so the result has no unit.

  • Variables: waist circumference and standing height, both in centimetres or both in inches. Age is not part of the formula.
  • Technical input ranges: waist 30–300 cm, height 80–250 cm, and optional age 5–120 as a whole number. These detect likely entry errors and are not medical boundaries.
  • The calculator uses full browser number precision and classifies the unrounded result. WHtR is shown to two decimals; converted inputs use up to four decimals and never feed rounded display values back into conversion.
  • Reference points: 0.40, 0.50, and 0.60 form descriptive adult bands. The half-height message follows NHS guidance; these are not diagnostic thresholds for every population.
Measurement and error

Measure waist horizontally at a consistent site at the end of a normal breath. Stand naturally without shoes for height. Small differences can change the displayed band near a reference point.

Who needs another standard
  • Children and adolescents need standards that account for age, sex, and growth stage.
  • Do not rely on this result during pregnancy, with ascites, after recent abdominal surgery, with marked swelling, or when standard measurement is not possible.
  • Population, age, medical condition, and clinical purpose can change the interpretation; 0.50 is not a universal diagnostic threshold.
  • The calculator does not assess body fat percentage, metabolic disease, or a personal treatment target.
Privacy and share links

The calculator does not upload or automatically save waist, height, or age and does not call a remote API. When you copy a share link, current measurements are written as plain URL parameters and may remain in chat history, browser history, or server logs.

Sources and update date

Content reviewed: 31 July 2026.

Health disclaimer

This result is for general health management only. It does not diagnose obesity, metabolic disease, or another condition and does not replace personalized medical advice.

Frequently asked questions

Does a WHtR of 0.50 always mean a health problem?

No. It is a practical adult screening reference point, not a diagnostic line. Risk changes continuously and also depends on age, population, measurement quality, medical history, and other indicators.

Can waist and height use different units?

No. Both measurements must use the same unit. You can choose centimetres or inches, and the ratio itself has no unit.

Why is age not used in the formula?

The mathematical formula uses only waist and height. Age is used to warn when an adult reference is unsuitable; people under 18 need age-, sex-, and growth-specific standards.

Is the half-height waist value a medical target?

No. It is simply height multiplied by 0.50 to explain the screening reference. It is not a diagnosis, prescription, or personalized treatment goal.