Waist-to-Height Ratio Calculator
A 175 cm tall adult with an 81 cm waist has a waist-to-height ratio of 0.46, or 46.3%, which sits in the healthy range used here. This waist-to-height ratio calculator divides waist by height, shows the result as a ratio and percent, and compares it with adult screening bands used by NICE. Enter waist and height in the same unit.
Quick answer
Waist-to-height ratio is waist divided by height.
Use the same unit for both measurements. This form does not convert between inches and centimeters.
What this tells you
- •Waist-to-height ratio is waist divided by height.
- •A ratio of 0.5 means your waist is half your height.
- •This tool uses the adult NICE bands 0.40 to 0.49, 0.50 to 0.59, and 0.60 or more.
- •The result is a screening marker, not a diagnosis.
How to Use
- 1Enter your waist measurement.
- 2Enter your height in the same unit.
- 3Calculate to see the ratio, percent, and category.
- 4Use the result as a screening check, then review it with a clinician if needed.
How It Works
Formula
Waist-to-height ratio = waist / height
Percent = (waist / height) x 100
Bands used here: below 0.40, 0.40 to 0.49, 0.50 to 0.59, 0.60 or more
Example: 81 / 175 = 0.4629, or 46.3%The calculator divides waist by height because both measurements use the same unit, so the units cancel out. It then restates the result as a percent and compares the ratio with the adult screening bands used by NICE and the Ashwell public health message to keep your waist under half your height.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Healthy range example
81 divided by 175 is 0.4629, which rounds to 0.46. That means the waist is 46.3% of height.
Increased health risk example
102 divided by 180 is 0.5667. That falls in the 0.50 to 0.59 band used here.
Adult Waist-to-Height Ratio Bands Used Here
These are the adult screening bands used in this calculator. NICE uses them to describe central adiposity risk in adults.
| Ratio band | Category shown here | How to read it |
|---|---|---|
| Below 0.40 | Below the common adult screening band | Below the main NICE adult table |
| 0.40 to 0.49 | Healthy range | No increased health risk in the NICE adult screening bands |
| 0.50 to 0.59 | Increased health risk | Increased central adiposity |
| 0.60 or more | High health risk | Further increased health risk |
Source basis: NICE adult waist-to-height ratio guidance and the Ashwell public health rule to keep your waist less than half your height. These bands are screening cutoffs for adults, not a diagnosis.
Common mistakes
- Mixing inches for waist with centimeters for height
- Measuring over bulky clothing or at different body landmarks each time
- Treating a screening band as a diagnosis or a full body composition assessment
Limitations
This calculator uses adult screening bands only. NICE applies the waist-to-height ratio table to adults, especially those with a BMI below 35, and the result does not account for age, ethnicity, pregnancy, muscle mass, how the waist was measured, or medical history. It is not intended for children.