Calculate your waist-to-height ratio from waist circumference and height, or find the waist size for a given height at a chosen ratio such as 0.5.

For NICE: measure midway between the bottom ribs and top of hips after breathing out naturally.

Adult screening interpretation
For adults 18+ with BMI below 35 kg/m², not in pregnancy.

Screening scope: This is not a diagnosis or treatment plan. Optional adult interpretation follows NICE NG246 for adults with BMI below 35kg/m², alongside BMI and clinical assessment. Listed bands are 0.4 to below 0.5, 0.5 to below 0.6, and 0.6 or more; a ratio below 0.4 is not assigned a health-risk classification here. Children, pregnancy and conditions affecting waist measurement need appropriate assessment. Hypothetical inverse calculations are not screened.

Waist-to-Height Ratio (WHtR) Formula

The following formula is used to calculate waist-to-height ratio (WHtR) from a measured waist circumference and height:

WHtR = WC / H

Variables:

  • WHtR is the waist-to-height ratio (unitless)
  • WC is waist circumference (use any length unit)
  • H is height (use the same length unit as WC)

To calculate WHtR, divide your waist circumference by your height. Any consistent units work (for example, inches/inches or cm/cm).

Reference Table: Waist at WHtR = 0.5 (waist = 0.5 × height)
Height (in) Waist where WHtR = 0.5 (in)
5829.00
5929.50
6030.00
6130.50
6231.00
6331.50
6432.00
6532.50
6633.00
6733.50
6834.00
6934.50
7035.00
7135.50
7236.00
7336.50
7437.00
7537.50
7638.00
7738.50
This table is a reference for WHtR = 0.5 (waist equals half of height). WHtR is calculated as waist ÷ height, using the same units for both.

What is Waist Circumference?

Waist circumference measures abdominal size. For the NICE method used with these bands, find the bottom ribs and top of the hips, wrap the tape horizontally midway between them, and breathe out naturally before reading. Other protocols use different landmarks; use the appropriate protocol consistently.

How to Calculate Waist-to-Height Ratio (WHtR)

The following steps outline how to calculate WHtR using your measured waist circumference and height:

  1. For NICE interpretation, measure waist circumference (WC) midway between the bottom ribs and top of the hips after breathing out naturally.
  2. Measure your height (H).
  3. Use the formula WHtR = WC ÷ H (make sure both measurements use the same units).
  4. Select Calculate to compute WHtR. Optionally select eligible adult interpretation; inverse tasks solve a chosen relationship and do not predict height or diagnose a measured waist.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Height (H) = 70 inches

Waist Circumference (WC) = 31.5 inches

Using the formula, the waist-to-height ratio (WHtR) would be:

WHtR = 31.5 ÷ 70 = 0.45