Waist Circumference Risk Calculator
Waist circumference is a simple, inexpensive measure that provides important information about cardiometabolic risk beyond what BMI alone can tell us. Central obesity (excess fat around the abdomen) is more metabolically harmful than fat stored elsewhere. The NIH and WHO use specific waist circumference thresholds to identify individuals at elevated risk for cardiovascular disease, type 2 diabetes, and metabolic syndrome. This calculator takes your waist circumference, hip circumference (optional), height, and sex to compute four metrics: waist risk category (NIH thresholds), waist-to-hip ratio (WHO thresholds), waist-to-height ratio, and an overall abdominal obesity assessment. Enter measurements in centimetres or inches.
Waist risk formulas
Waist-to-hip ratio = Waist / Hip
Waist-to-height ratio = Waist / Height
NIH high risk: Men >102 cm (40 in), Women >88 cm (35 in)
WHO WHR high risk: Men >0.90, Women >0.85
Healthy WHtR: ≤0.50 for adults
Waist circumference: frequently asked questions
Why does waist circumference matter for health?
Waist circumference is one of the best simple indicators of central (abdominal) obesity, which is associated with visceral fat. Excess visceral fat is linked to insulin resistance, type 2 diabetes, high blood pressure, cardiovascular disease, and metabolic syndrome, independent of BMI.
What is the NIH high-risk waist circumference?
The National Heart, Lung, and Blood Institute defines high risk as a waist circumference above 40 inches (102 cm) for men and above 35 inches (88 cm) for women. These cut-offs are used in diagnosing metabolic syndrome.
What is the waist-to-hip ratio?
The waist-to-hip ratio (WHR) is calculated by dividing waist circumference by hip circumference. The WHO defines abdominal obesity as WHR above 0.90 for men and above 0.85 for women. WHR is a stronger predictor of heart attack risk than BMI in some studies.
What is the waist-to-height ratio and what is healthy?
Waist-to-height ratio (WHtR) is waist circumference divided by height (both in the same unit). A WHtR of 0.5 or less is generally associated with low cardiometabolic risk. The practical rule is: keep your waist to less than half your height.
How do I measure my waist circumference correctly?
Stand relaxed, exhale normally, and measure at the midpoint between the bottom of the lowest rib and the top of the iliac crest (hip bone). For most people this is approximately at the level of the navel. Use a flexible tape measure, snug but not compressing the skin.
Official sources
- National Heart, Lung, and Blood Institute: Assessing Your Weight and Health Risk.
- World Health Organization: Waist Circumference and Waist-Hip Ratio Report.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.