Waist-to-Height Ratio Calculator — NICE Categories & Target Waist
Calculate your waist-to-height ratio (WHtR), see which NICE central adiposity category it falls in, and find the waist size that keeps your waist below half your height.
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Waist Thresholds by Height
Waist sizes at each NICE boundary for heights near yours.
| Height | 0.4 (lower healthy) | 0.5 (increased from) | 0.6 (high from) |
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How this calculator works
WHtR = waist circumference ÷ height, both in the same unit — so the ratio has no units. The result is classified using the NICE adult categories:
- 0.4 to 0.49: healthy central adiposity — no increased health risks
- 0.5 to 0.59: increased central adiposity — increased health risks
- 0.6 or more: high central adiposity — further increased health risks
NICE recommends these classifications for adults with a BMI under 35, of both sexes and all ethnicities, including adults with high muscle mass. Ratios below 0.4 aren't a NICE category; if yours is that low, check your BMI to make sure you're not underweight.
By Suhaib Hassan · Reviewed 28 September 2026 against NICE guidance · How CalculatePilot verifies formulas →
The 'keep your waist below half your height' guideline
Waist-to-height ratio is built around a simple public health message: keeping your waist circumference under half your height is associated with lower cardiometabolic risk. A 2012 meta-analysis by Ashwell and colleagues found WHtR was a better screening tool for cardiometabolic risk than waist circumference or BMI, because it captures fat carried around the middle — which is more strongly linked to health risk than overall body weight.
A worked example
Someone 170 cm tall with a 95 cm waist: 95 ÷ 170 = 0.56, which is "increased central adiposity". Half their height is 85 cm, so a waist below 85 cm would bring the ratio under 0.5 — a reduction of 10 cm.
How it complements other measures
No single measure tells the whole story — waist-to-height ratio, BMI and waist-to-hip ratio each capture a different aspect of body composition and risk. NICE suggests using WHtR alongside BMI. This is a screening tool for general awareness, not a diagnosis; a healthcare provider can interpret it in the context of your full health picture.
Sources
- NICE guideline NG246 — Overweight and obesity management (waist-to-height ratio recommendations)
- Ashwell M, Gunn P, Gibson S. Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis. Obes Rev 2012;13:275–286.
- World Health Organization. Waist circumference and waist–hip ratio: report of a WHO expert consultation. Geneva, 2008.
Frequently asked questions
Do I need to convert units before entering my measurements?
No — just make sure both waist and height are in the same unit (both inches or both centimetres), since the ratio itself is unitless as long as they match.
Is waist-to-height ratio better than BMI?
They measure different things. Research suggests waist-to-height ratio is a better indicator of central fat and related cardiometabolic risk, but most health professionals — including NICE — view the two as complementary rather than one replacing the other.
Where exactly should I measure my waist?
Find the bottom of your lowest rib and the top of your hip bone, and measure around your body midway between them, keeping the tape level and snug but not compressing the skin. Breathe out normally before reading the tape.
What waist-to-height ratio is healthy?
NICE classes 0.4 to 0.49 as healthy central adiposity for adults. From 0.5 health risks are increased, and from 0.6 they are further increased.
Related Calculators
Other views of body shape and composition.