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

> Waist-to-hip ratio and waist-to-height ratio from tape measurements, with the WHO risk cut-offs, the NICE bands and the WHO waist size category.

Interactive version: https://www.calcopenly.com/health/waist-to-hip-ratio-calculator
Subject: Health and fitness calculators

Waist-to-hip ratio (WHR) is waist circumference divided by hip circumference, and waist-to-height ratio (WHtR) is waist divided by height in the same unit. Both measure fat carried around the middle, which BMI misses. WHR is compared with the WHO 2008 cut-offs of 0.90 for men and 0.85 for women, and waist size alone with the WHO thresholds of 94 and 102 cm for men and 80 and 88 cm for women.

People use these ratios to screen for central obesity, which is linked to type 2 diabetes and cardiovascular disease. With the defaults, a man with an 86 cm waist, 100 cm hips and a height of 175 cm has a WHR of 0.86, below the WHO cut-off, and a WHtR of 0.49, inside NICE's healthy band of 0.4 to 0.49.

The cut-offs are population thresholds, mostly set in Europid adults, not diagnoses. They assume the WHO method: waist midway between the lowest rib and the top of the hip bone after a normal breath out.

## Inputs

- **Sex (for the formula)** (options: Male, Female)
- **Waist**: Midway between the lowest rib and the top of the hip bone, after breathing out
- **Hip**: Around the widest part of the buttocks
- **Height**: Accepts 5'11" or 5 ft 11 in

## Results

- Waist-to-hip ratio — main result
- WHR risk (WHO)
- Waist-to-height ratio
- WHtR band (NICE)
- Waist circumference risk (WHO)

## Formula

$$
\text{WHR} = \frac{\text{waist}}{\text{hip}},\qquad \text{WHtR} = \frac{\text{waist}}{\text{height}}
$$

## Worked examples

### Boundary: man with WHR exactly 0.90

- Sex (for the formula): Male
- Waist: 90 cm
- Hip: 100 cm
- Height: 175 cm
- **Waist-to-hip ratio: 0.90**
- **WHR risk (WHO): Substantially increased**
- **Waist-to-height ratio: 0.51**
- **WHtR band (NICE): Increased**
- **Waist circumference risk (WHO): Not increased**
- Checked against: 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

### Woman, waist 70, hip 98, 165 cm

- Sex (for the formula): Female
- Waist: 70 cm
- Hip: 98 cm
- Height: 165 cm
- **Waist-to-hip ratio: 0.71**
- **WHR risk (WHO): Not increased**
- **Waist-to-height ratio: 0.42**
- **WHtR band (NICE): Healthy**
- **Waist circumference risk (WHO): Not increased**
- Checked against: Python 3.8 decimal: 70/98 = 0.7143 < 0.85; 70/165 = 0.4242 in NICE 0.4–0.49

### Inches: waist 40, hip 38, 6 ft

- Sex (for the formula): Male
- Waist: 40 in
- Hip: 38 in
- Height: 6 ft
- **Waist-to-hip ratio: 1.05**
- **WHR risk (WHO): Substantially increased**
- **Waist-to-height ratio: 0.56**
- **Waist circumference risk (WHO): Increased**
- Checked against: Python 3.8 decimal: 40/38 = 1.0526; 40/72 = 0.5556; 101.6 cm is above 94 cm but not above 102 cm (WHO)

### Boundary: waist-to-height exactly 0.5

- Sex (for the formula): Male
- Waist: 85 cm
- Hip: 100 cm
- Height: 170 cm
- **Waist-to-height ratio: 0.50**
- **WHtR band (NICE): Increased**
- **Waist-to-hip ratio: 0.85**
- **WHR risk (WHO): Not increased**
- Checked against: Hand calculation: 85/170 = 0.5, the start of NICE's 0.5–0.59 increased-risk band

### Woman above all cut-offs

- Sex (for the formula): Female
- Waist: 90 cm
- Hip: 100 cm
- Height: 160 cm
- **Waist-to-hip ratio: 0.90**
- **WHR risk (WHO): Substantially increased**
- **Waist-to-height ratio: 0.56**
- **Waist circumference risk (WHO): Substantially increased**
- Checked against: Hand calculation: 0.90 ≥ 0.85; 90/160 = 0.5625; 90 cm > 88 cm (WHO women)

## Questions

### What is a healthy waist-to-hip ratio?

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.

### What waist size is a health risk?

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.

### What is a good waist-to-height ratio?

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.

### How do you measure waist and hip circumference?

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.

### How accurate is the waist-to-hip and waist-to-height ratio calculator?

Accuracy depends on your inputs and the method's assumptions. Decimal arithmetic uses 50 significant digits, but estimates, numerical methods and source data can be less precise; the displayed rounding does not remove those limits. It is checked against 5 worked examples whose answers come from independent sources; for example, “Boundary: man with WHR exactly 0.90” is checked against 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.

### Where does the method come from?

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.

## Sources

- [WHO. Waist circumference and waist–hip ratio: report of a WHO expert consultation, Geneva, 8–11 December 2008 (published 2011)](https://www.who.int/publications/i/item/9789241501491)
- [NICE. Obesity: identification, assessment and management (CG189), 2022 update — waist-to-height ratio](https://www.nice.org.uk/guidance/cg189)
- 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

_Note: medical information, not professional advice._