How to use the waist-to-height ratio calculator
Choose centimeters or inches, then enter your waist circumference and height. Both measurements must use the same unit. If your height is in feet and inches, multiply the feet by 12 and add the remaining inches: 5 feet 7 inches becomes 67 inches.
The calculator shows the ratio immediately. To see an adult reference band, confirm that you meet the eligibility criteria. If you do not know your BMI, use our adult BMI calculator first. Switching measurement units converts the values already entered.
How to measure your waist
Locate the lower edge of your ribs and the upper edge of your hip bones. Take the waist measurement halfway between them, with the tape around your middle. Read it after a normal breath out. This follows the measurement approach described by NICE.
Use a measured waist circumference rather than a clothing size. Check the unit printed on the tape before entering the number. Repeating the measurement can help catch a reading or typing mistake.
The WHtR formula and a worked example
Waist-to-height ratio = waist circumference ÷ height. The units cancel, leaving a number rather than centimeters, inches or a percentage of body fat.
For a waist of 80 cm and height of 170 cm, 80 ÷ 170 = approximately 0.471. Half that height is 85 cm, corresponding to a ratio of 0.5. With the same height, a waist of 102 cm gives exactly 0.6. These examples illustrate the arithmetic, not an individual recommendation to change waist size.
Adult reference bands
NICE recommends using waist-to-height ratio alongside BMI in adults with BMI below 35. The following bands describe central adiposity, meaning fat around the abdomen.
| Unrounded ratio | Reference label |
|---|---|
| 0.4 to below 0.5 | Healthy central adiposity |
| 0.5 to below 0.6 | Increased central adiposity |
| 0.6 or above | High central adiposity |
A result below 0.4 is outside these listed bands. We do not label it as healthier. The classification uses the full calculation rather than the rounded display, so a result just below a boundary stays in the lower band.
Waist-to-height ratio versus BMI and body-fat percentage
These tools answer different questions. BMI compares weight with height squared. WHtR compares waist circumference with height. Our body-fat calculator uses a separate circumference formula to estimate a percentage. A WHtR of 0.5 does not mean 50% body fat.
None of these outputs alone gives a complete picture of health. Use the appropriate instructions for each tool; do not substitute a waist-to-height result for a diagnosis or a treatment plan.
Who is this calculator for?
This version provides adult interpretation only, for people aged 18 or older with BMI below 35. It does not provide a child assessment. Following NHS exclusions, do not use it during pregnancy, with a diagnosed or suspected eating disorder, or with a growth disorder or other condition affecting height.
The checkbox controls whether the page displays an interpretation; it is not a medical screening assessment. If the tool is unsuitable or a result concerns you, a healthcare professional can advise on a more appropriate assessment.
Frequently asked questions
Is waist-to-height ratio the same as waist-to-hip ratio?
No. Waist-to-hip ratio uses hip circumference as the denominator. This tool uses height and does not ask for a hip measurement.
Why did switching units leave my ratio unchanged?
Converting both measurements by the same factor leaves their quotient unchanged. Small display differences may reflect decimal precision.
Can I use this to set a weight-loss target?
The output does not calculate a calorie intake, goal weight or treatment target. The half-height number is an arithmetic reference only.
Sources
- NICE NG246: Identifying and assessing overweight, obesity and central adiposity — measurement method and adult interpretation.
- NHS: Calculate your waist to height ratio — scope and exclusions.
Sources checked October 12, 2026. This is an independently implemented educational calculator, not an endorsement by NICE or the NHS.