Quick guide
How to use this calculator
- Use the labels and unit notes to enter the requested measurement, date, time, or observation exactly as recorded.
- Check the visible method, population, and unit basis before using the result; switch modes rather than converting values mentally.
- Read the calculation audit and limitations together. The result supports measurement or tracking and does not replace diagnosis, treatment, or urgent medical assessment.
Calculation method
How the waist-to-height ratio calculator works
Waist-to-height ratio = waist circumference ÷ height. Because the units cancel, centimetres and inches produce the same ratio when used consistently.
NICE names 0.4–0.49 as healthy central adiposity, 0.5–0.59 as increased, and 0.6 or more as high. A result below 0.4 is shown outside those named bands so the measurement can be rechecked. The separate public message to keep waist below half of height does not turn every lower value into a named classification.
Worked example
Waist-to-Height Ratio example
A waist of 82 cm and height of 175 cm gives 0.469, meaning the waist is 46.9% of height.
Waist-to-height ratio = waist circumference ÷ height. Because the units cancel, centimetres and inches produce the same ratio when used consistently.
Supported inputs
Precision and limits
Supported purpose
The displayed NICE bands are UK guidance for adults and do not replace individualized assessment. NICE recommends waist-to-height ratio as an additional measure in adults with BMI below 35 kg/m² and notes it may be less useful at BMI 35 or above. Measurement location and technique must be consistent; pregnancy and conditions affecting waist measurement are excluded.
Measurement quality
The output is only as reliable as the entered measurement, device, timing, units, and applicable reference population. Recheck unexpected values against the original record.
Clinical boundary
This calculator does not diagnose a condition, choose treatment, change medication, or determine that an urgent symptom is safe to monitor at home. Contact an appropriate health professional or local emergency service when the situation may be urgent.
Privacy
Entered health values and results stay in this browser tab. They are not placed in URLs, analytics, logs, local storage, session replay, or a cloud record by this calculator.
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