Waist-to-Height Ratio
The rule is simply "keep your waist under half your height". Several studies find it predicts cardiometabolic risk better than BMI.
Your numbers
Waist-height ratio
0.5
Result
85cm
What it means
0.5 is over 0.5 — your waist exceeds half your height.
Formula
Waist-height ratio = Waist (cm) ÷ Height (cm)
The 0.5 line applies to both children and adults, and the units cancel out — centimetres or inches both work.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Waist (cm)Waist at navel height, measured after breathing out. | 85 | 40 ~ 200 |
| Height (cm)Height in centimetres; converted to metres inside the formula. | 170 | 100 ~ 250 |
Step by step
Quick reference table
Results when only Waist (cm) changes and everything else stays put.
| Waist (cm) | Waist-height ratio | Result (cm) |
|---|---|---|
| 42.5 | 0.25 | 85 |
| 63.8 | 0.375 | 85 |
| 85 | 0.5 | 85 |
| 128 | 0.753 | 85 |
| 170 | 1 | 85 |
What each result means
| Result | At default values |
|---|---|
| Waist-height ratioWaist over height; the line people watch is 0.5. | 0.5 |
| Result (cm)What the formula gives back — the answer this page is for. | 85 |
Common mistakes
The 0.5 line applies to both children and adults, and the units cancel out — centimetres or inches both work.
Glossary
- Waist (cm)
- Waist at navel height, measured after breathing out.
- Height (cm)
- Height in centimetres; converted to metres inside the formula.
- Waist-height ratio
- Waist over height; the line people watch is 0.5.
- Result
- What the formula gives back — the answer this page is for.
Frequently asked questions
Q. How is Waist-to-Height Ratio calculated?
Waist-height ratio = Waist (cm) ÷ Height (cm) — The rule is simply "keep your waist under half your height". Several studies find it predicts cardiometabolic risk better than BMI.
Q. Can you walk through an example?
With Waist (cm) 85, Height (cm) 170, the answer is Waist-height ratio 0.5.
Q. What do I need to enter?
Enter Waist (cm), Height (cm). The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Waist (cm) moves the answer to Waist (cm) 42.5 → Waist-height ratio 0.25 and Waist (cm) 170 → Waist-height ratio 1. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
The 0.5 line applies to both children and adults, and the units cancel out — centimetres or inches both work.
Related calculators
These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.