Waist-to-hip and waist-to-height ratio calculator

Below 0.90 for men and below 0.85 for women, the cut-offs at which a 2008 WHO expert consultation placed substantially increased risk of metabolic complications. A man with an 86 cm waist and 100 cm hips has 0.86, under the line; the same waist with 94 cm hips gives 0.91, over it. These are population thresholds, so a ratio near the line says little about one person on its own.

WHO links a waist above 94 cm (37 in) in men and 80 cm (31.5 in) in women to increased risk of metabolic complications, and above 102 cm (40 in) and 88 cm (34.6 in) to substantially increased risk. These cut-offs come mainly from Europid populations. The International Diabetes Federation uses lower thresholds for South Asian and Chinese adults: 90 cm for men and 80 cm for women.

Under 0.5, the basis of the public-health message to keep your waist to less than half your height. NICE's bands, added to its obesity guidance in 2022, are 0.4 to 0.49 healthy, 0.5 to 0.59 increased and 0.6 or more high central adiposity. A 2012 meta-analysis by Ashwell and colleagues found WHtR a better screen for cardiometabolic risk than waist circumference or BMI.

WHO measures the waist midway between the lowest rib and the top of the hip bone at the end of a normal breath out, and the hips around the widest part of the buttocks, with the tape level and snug but not compressing the skin. The published cut-offs assume this method. Measuring at the navel gives a different number, and a 2 cm change in waist moves the ratio by 0.02 when hips are 100 cm.

Độ chính xác phụ thuộc vào dữ liệu nhập và giả định của phương pháp. Phép tính thập phân dùng 50 chữ số có nghĩa, nhưng ước lượng, phương pháp số và dữ liệu nguồn có thể kém chính xác hơn; làm tròn khi hiển thị không loại bỏ các giới hạn đó. Ví dụ có lời giải đã đối chiếu với nguồn độc lập: 5. Ví dụ, “Boundary: man with WHR exactly 0.90” được kiểm tra bằng Python 3.8 decimal: 90/100 = 0.90 meets the WHO ≥ 0.90 cut-off; 90/175 = 0.5143 is in NICE's 0.5–0.59 band; 90 cm ≤ 94 cm.

WHO. Waist circumference and waist–hip ratio: report of a WHO expert consultation, Geneva, 8–11 December 2008 (published 2011); NICE. Obesity: identification, assessment and management (CG189), 2022 update — waist-to-height ratio; Ashwell M, Gunn P, Gibson S. Waist-to-height ratio is a better screening tool than waist circumference and BMI. Obes Rev 2012;13:275–286.