# Waist-to-height ratio (WHtR)

The simplest central-fat measure: keep your waist under half your height. The measure behind VT’s metabolic age and part of the Vitality Score.

Type: body_value · Unit: ratio · Domain: Body Composition · Accuracy: Calculated · Importance: Core

Also called: waist to height, half your height rule

## In one sentence

Your waist divided by your height, the simplest measure of central fat there is, and the one behind the rule people remember: keep your waist under half your height.

## Why it matters

Dividing by height removes the obvious objection to a raw waist, that tall people have bigger middles, and the result works across ages, sexes and populations in a way BMI does not. The 0.5 boundary comes from two reviews: one found that the ratio separated adults with and without raised blood pressure, blood fats and glucose better than BMI or waist alone in 31 studies (Ashwell 2012); an earlier review of 78 studies across 14 countries found 0.5 to be a sensible single boundary across them (Browning 2010). It is a published reference point, not a line Vitality Tracker draws for you.

## What moves it

The waist; height is fixed. Everything in the waist entry applies, including the site.

## How Vitality Tracker uses it

It is the central-fat input to the Vitality Score's body-composition area and, through the cube root of the same ratio, one of the two shape terms in your metabolic age, where it is the term that moves the result: about a third of a year per centimeter of waist at a fixed weight.

## How far to trust the number

As good as the waist that went into it, and no better.

## Method

WHtR = waist (cm) ÷ height (cm). A 1.78 m person with an 88 cm waist has 0.494.

## Sources

1. Ashwell M, Gunn P, Gibson S. Obes Rev 2012;13:275–86. [doi:10.1111/j.1467-789X.2011.00952.x](https://doi.org/10.1111/j.1467-789X.2011.00952.x)
2. Browning LM, Hsieh SD, Ashwell M. A systematic review of waist-to-height ratio as a screening tool for the prediction of cardiovascular disease and diabetes: 0.5 could be a suitable global boundary value. Nutr Res Rev 2010;23:247–69. [doi:10.1017/S0954422410000144](https://doi.org/10.1017/S0954422410000144).

## Related

- [Waist and hip circumference](https://vitalitytracker.app/knowledge/waist-and-hip)
- [How to measure your waist](https://vitalitytracker.app/knowledge/how-to-measure-your-waist)
- [Waist-to-hip ratio](https://vitalitytracker.app/knowledge/waist-to-hip-ratio)
- [Metabolic age](https://vitalitytracker.app/knowledge/metabolic-age)
- [Vitality Score](https://vitalitytracker.app/knowledge/vitality-score)

Reviewed October 2026 · v1

Source: https://vitalitytracker.app/knowledge/waist-to-height-ratio