Waist-to-Height Ratio Calculator
Divide waist by height to gauge health risk — a simple predictor that rivals BMI
Use the same unit for both (inches or cm) — the ratio is unitless.
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Quick summary
Enter your waist and height in the same unit to get your waist-to-height ratio (WHtR). The simple guideline is to keep your waist under half your height — a ratio below 0.5. Ratios of 0.5–0.6 signal increased cardiometabolic risk and 0.6+ high risk. Because it focuses on central (belly) fat, WHtR predicts heart and metabolic risk at least as well as BMI, and it's easy to measure at home.
Reviewed by Simple Calculators TeamLast reviewed
For information only — not medical advice. Results are estimates from published formulas and can't account for your health history. Talk to a doctor or other qualified clinician before making health decisions.
How to use this calculator
- Enter the inputs requested by the calculator.
- Choose the units or options that match your situation and review the assumptions.
- Run or update the calculation to see the result.
- Review the result, breakdown, and formulas shown on the page.
- Check the inputs, units, dates, and limitations before saving or sharing the result.
Frequently asked questions
What is a healthy waist-to-height ratio?
Below 0.5 is considered healthy for most adults — meaning your waist is less than half your height. From 0.5 to 0.6 indicates increased risk, and 0.6 or above suggests high cardiometabolic risk. The 'keep your waist under half your height' rule is easy to remember and applies across most heights.
How do I measure my waist correctly?
Measure around your bare abdomen at the level of your belly button (roughly midway between the bottom of your ribs and the top of your hip bones), after breathing out normally. Keep the tape snug but not compressing the skin. Use the same unit — inches or centimeters — for both waist and height.
Is waist-to-height ratio better than BMI?
It's a useful complement. BMI doesn't distinguish fat from muscle or show where fat is stored, whereas waist-to-height ratio targets central (abdominal) fat, which carries the most metabolic risk. Studies find WHtR predicts heart disease and diabetes risk at least as well as BMI, and often better.
Does the ratio depend on units?
No — because it's a ratio of two lengths, the units cancel out, as long as you use the same unit for both measurements. Waist 34 inches ÷ height 68 inches gives 0.5, exactly the same as measuring both in centimeters. Just don't mix inches and centimeters.
Key terms
- Waist-to-Height Ratio
- Waist divided by height; a central-obesity risk measure.
- Central Obesity
- Excess fat around the abdomen, the highest-risk fat pattern.
- 0.5 Guideline
- Keeping your waist under half your height is the healthy target.
Methodology, sources & limitations
This page shows the formula, assumptions, and limitations used for this estimate. Rates, thresholds, and other time-sensitive inputs can change, so verify them against the relevant official source before relying on a result.
For our review approach and the primary sources we consult, see the methodology and source policy. If you spot an outdated figure or formula, please contact us with a correction.