Who should not use this calculator: Not for children under 5, pregnancy, eating disorders, growth disorders or other conditions affecting height, or adults with BMI over 35. Results may be misleading in these cases.

Use this Waist-to-Height Ratio (WHtR) Calculator to check your WHtR, see your waist-risk category, and compare your waist with the common half-height target. It is a simple screening tool for central fat distribution and is often used alongside BMI when looking at weight-related health risk.

Reviewed by: AjaxCalculators Editorial Team
Last updated: April 23, 2026
Method source: Waist-to-height ratio screening using waist circumference divided by height, with NICE category thresholds for central adiposity
Editorial standards: AjaxCalculators Editorial Policy

What This Waist-to-Height Ratio (WHtR) Calculator Calculates

This calculator estimates:

• Waist-to-height ratio (WHtR)
• Waist-to-height category
• Half-height waist target

On the live tool, it also shows waist-to-hip ratio (WHR), but the main purpose of this page is to calculate and interpret WHtR.

How the Waist-to-Height Ratio (WHtR) Calculator Works

The formula is simple:

WHtR = waist circumference ÷ height

Because both measurements use the same unit, the unit cancels out. That means the result is the same whether you enter both measurements in centimeters or both in inches.

Example:

• Waist = 80 cm
• Height = 170 cm

WHtR = 80 ÷ 170 ≈ 0.47

A commonly used public-health message is:

Keep your waist to less than half your height

That means a WHtR under 0.5 is often used as the main practical target.

How to Interpret Waist to Height Ratio

NICE classifies central adiposity using the following WHtR ranges:

• 0.4 to 0.49 = healthy central adiposity
• 0.5 to 0.59 = increased central adiposity
• 0.6 or more = high central adiposity

These categories are used for adults and for children and young people aged 5 years and over. NICE also recommends explaining the result in simple terms: try to keep your waist to less than half your height.

Assumptions and Important Notes

• This calculator is a screening tool, not a diagnosis.
• It should not be used for children under 5 years old.
• It should not be used during pregnancy.
• It is also not suitable if height is affected by a growth disorder or another condition that changes usual body proportions.
• NHS also advises adults with BMI over 35 not to use the public WHtR calculator in the usual way.
• Measurement technique matters. Waist should be measured consistently and correctly.

Worked Example

Suppose someone has:

• Height: 175 cm
• Waist: 88 cm

Step 1: Use the WHtR formula
WHtR = waist ÷ height

Step 2: Substitute the values
WHtR = 88 ÷ 175

Step 3: Calculate
WHtR ≈ 0.50

Step 4: Interpret the result
A WHtR of about 0.50 sits at the boundary where NICE moves from the healthy range into the increased-risk range.

Step 5: Check the half-height target
Half of 175 cm = 87.5 cm

So this person’s waist is slightly above the “waist under half your height” rule-of-thumb target.

How to Use This Waist-to-Height Ratio (WHtR) Calculator

1. Enter your height.
2. Enter your waist circumference.
3. Use the same unit for both measurements.
4. Click Calculate to see your WHtR, category, and half-height target.
5. If you also want waist-to-hip information, use the hip field shown on the live tool or visit the broader waist-ratio calculator page.

How to Interpret the Result

WHtR tells you how large your waist is relative to your height.

Half-height waist target gives a quick rule-of-thumb threshold that is easy to remember.

A higher WHtR usually suggests more central fat around the abdomen, which is why NICE uses it as a practical measure of central adiposity risk.

This is still a screening measure. It should be interpreted alongside BMI, medical history, blood pressure, blood lipids, glucose status, and clinical judgement.

Practical Uses of a Waist-to-Height Ratio (WHtR) Calculator

• screen for central adiposity
• compare waist size with the half-height target
• use alongside BMI for a fuller body-shape picture
• track waist-related risk changes over time
• understand why two people with the same BMI may have different waist-related risk patterns

References

1. NICE guideline NG246: WHtR categories for adults and children aged 5 years and over
2. NICE public message: keep your waist less than half your height
3. NHS waist-to-height calculator guidance and exclusion notes
4. Endotext: waist circumference remains an important practical adiposity-risk measure

Related Calculators

• Waist to Hip and Height Ratio Calculator
• ABSI Calculator
• Body Fat Calculator
• Calorie Calculator

Disclaimer: This calculator is for educational and screening use only. It should not be used to diagnose any condition. If you are concerned about your waist size or cardiometabolic risk, speak with a clinician.