Waist to Hip Ratio Calculator
Calculate your waist-to-hip ratio and waist-to-height ratio from tape measurements in centimetres or inches, with the WHO risk bands for men and women.
Waist circumference on its own
Your waist of 80.0 cm (31.5 in) is increased risk. The usual thresholds are 80 cm (31.5 in) and 88 cm (34.6 in) for women.
Risk bands used
| Band | Men | Women |
|---|---|---|
| Low risk | below 0.90 | below 0.80 |
| Moderate risk | 0.90 – 0.99 | 0.80 – 0.84 |
| High risk | 1.00 and above | 0.85 and above |
This is a screening signal, not a diagnosis. The result is highly sensitive to tape placement — a couple of centimetres of drift at the waist can move you between bands — and the WHO cut-offs were derived largely from European-descent populations, with lower thresholds recommended for South Asian and some East Asian populations. A result in a higher band is a reason to speak to a doctor, not a conclusion on its own.
What is the Waist to Hip Ratio Calculator?
Waist-to-hip ratio is waist circumference divided by hip circumference. The World Health Organization considers a ratio above 0.90 in men and above 0.85 in women to indicate abdominal obesity and raised metabolic risk.
- Waist-to-hip ratio with WHO risk bands by sex
- Waist-to-height ratio with the 0.5 boundary
- Absolute waist-circumference thresholds included
- Centimetres and inches supported
- Clear guidance on where to place the tape
- Everything computed locally — measurements never leave your device
How to use the Waist to Hip Ratio Calculator
- 1
Choose centimetres or inches.
- 2
Select your sex, since the risk thresholds differ.
- 3
Measure your waist at the narrowest point, midway between the lowest rib and the hip bone.
- 4
Measure your hips at their widest point, and enter both figures.
- 5
Optionally add your height to see your waist-to-height ratio too.
About the Waist to Hip Ratio Calculator
The ByteTools Waist to Hip Ratio Calculator divides your waist measurement by your hip measurement and places the result in the World Health Organization risk bands for your sex. Because it measures where fat sits rather than how much you weigh, it captures something BMI misses entirely — abdominal fat is the pattern most strongly linked to metabolic risk.
Enter measurements in centimetres or inches. Add your height and the tool also reports your waist-to-height ratio, a simple 'keep your waist under half your height' check that some researchers argue is a better single screening number than either BMI or WHR.
All calculation happens in your browser and no measurements are uploaded or saved. This is a screening estimate, not a diagnosis and not medical advice — a ratio in a higher band is a reason to talk to a doctor, not a conclusion about your health on its own.
Frequently asked questions
What is a good waist to hip ratio?
The WHO puts substantially raised risk at a ratio of 0.90 or above for men and 0.85 or above for women. Below those thresholds is generally considered low risk, though the relationship is a gradient rather than a switch that flips at a single value.
How do I measure waist to hip ratio?
Stand relaxed and breathe out normally. Measure your waist at its narrowest point, roughly midway between your lowest rib and the top of your hip bone, then measure your hips at their widest point around the buttocks. Divide waist by hips — a 80 cm waist and 100 cm hips give a ratio of 0.80.
How reliable is waist-to-hip ratio as a health measure?
It predicts cardiovascular and metabolic risk better than BMI in several large cohort studies, but its accuracy depends heavily on tape placement — a couple of centimetres of drift at the waist changes the ratio enough to move you between bands. The WHO cut-offs also come mostly from European-descent populations, and lower thresholds are recommended for South Asian and some East Asian populations. It is a screening signal, never a diagnosis.
Is waist to hip ratio better than BMI?
For predicting metabolic and cardiovascular risk, waist-based measures generally do better, because they reflect where fat is stored rather than just total mass. BMI is easier to measure consistently, so in practice the two are best used together.
What is waist-to-height ratio?
It is your waist circumference divided by your height, in the same units. The simple guideline is to keep your waist under half your height — a ratio below 0.5. It needs no sex-specific thresholds and works reasonably well for both adults and children.
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