acalculator

What is my waist to height ratio?

Type your waist measurement and your height. The waist to height ratio calculator divides them, places the ratio against the 0.5 and 0.6 boundaries, and shows the waist size that equals half your height.

Your numbers

Units
Waist-to-height ratio
0.457

A 32 in waist at a height of 5 ft 10 in gives a waist-to-height ratio of 0.457: No increased risk.

No increased risk

  1. No increased risk
  2. Increased risk
  3. Very high risk
Risk group
No increased risk
Waist at a ratio of 0.5 (in)
35
Waist at a ratio of 0.5 (cm)
88.9

Waist-to-height ratio: 0.457. A 32 in waist at a height of 5 ft 10 in gives a waist-to-height ratio of 0.457: No increased risk.

Where does my ratio fall?

This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use

How to calculate

Divides your waist circumference by your height and compares the waist-to-height ratio (WHtR) with the 0.5 and 0.6 boundaries for early health risk, with the largest waist that keeps the ratio below 0.5.

Example with the default inputs (Waist 32 in, Height 5 ft 10 in): A 32 in waist at a height of 5 ft 10 in gives a waist-to-height ratio of 0.457: No increased risk.

Method: Waist-to-height ratio = waist ÷ height; below 0.5 no increased risk, 0.5 to below 0.6 increased risk, 0.6 or more very high risk.

  • The same boundaries apply to adult men and women (Ashwell and Gibson, 2016).
  • Waist measured midway between the lowest rib and the top of the hip bone; height without shoes.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Waist 34 in, Height 5 ft 8 in gives Waist-to-height ratio 0.5, Risk group Increased risk, Waist at a ratio of 0.5 (in) 34.Source: Ashwell and Gibson, 2016, Waist-to-height ratio as an indicator of ‘early health risk’, BMJ Open 6:e010159 (WHtR < 0.5 no increased risk, 0.5 to < 0.6 increased risk, ≥ 0.6 very high risk), https://pubmed.ncbi.nlm.nih.gov/26975935/
  2. Waist 31.5 in, Height 5 ft 8.9 in gives Waist-to-height ratio 0.457143, Risk group No increased risk, Waist at a ratio of 0.5 (cm) 87.5.Source: Ashwell and Gibson, 2016, Waist-to-height ratio as an indicator of ‘early health risk’, BMJ Open 6:e010159 (WHtR < 0.5 no increased risk, 0.5 to < 0.6 increased risk, ≥ 0.6 very high risk), https://pubmed.ncbi.nlm.nih.gov/26975935/
  3. Waist 37.8 in, Height 5 ft 3 in gives Waist-to-height ratio 0.6, Risk group Very high risk.Source: Ashwell and Gibson, 2016, Waist-to-height ratio as an indicator of ‘early health risk’, BMJ Open 6:e010159 (WHtR < 0.5 no increased risk, 0.5 to < 0.6 increased risk, ≥ 0.6 very high risk), https://pubmed.ncbi.nlm.nih.gov/26975935/

How it works

  • Waist-to-height ratio (WHtR) = waist circumference ÷ height.
  • Risk group (Ashwell and Gibson, 2016): below 0.5 is no increased risk; 0.5 up to but not including 0.6 is increased risk; 0.6 or more is very high risk. A ratio of exactly 0.5 is in the increased-risk group.
  • Waist at a ratio of 0.5 = height ÷ 2: the waist size at the boundary, shown in inches and in centimetres.

Rules. The waist is from 10 cm to 300 cm; the height from 50 cm to 275 cm. A waist more than 1.5 times the height gives no answer, because a measurement or unit is probably wrong.

Exact arithmetic. Each measurement is read as the exact decimal you typed, in the unit you typed it in (5 ft 8 in is exactly 68 in), so 34 in ÷ 68 in is exactly 0.5. When you type in a unit, the page stores the size in metres and reads it back as the decimal with the fewest significant digits, in one of the box's units, that gives the same stored number (a feet-and-inches pair counts by its value in inches; on a tie the first unit in the menu wins). The ratio is compared with 0.5 and 0.6 exactly.

Output format. Decimals and significant figures below are the most shown; trailing zeros are dropped (23.0 shows as 23, money keeps its cents). The ratio shows 3 decimals, rounded half up from its decimal value. The waist at 0.5 shows 1 decimal in inches and 1 decimal in centimetres, each worked out exactly in that unit and rounded half up (79.9 in tall gives 39.95 in, shown 40.0). 1 in = 2.54 cm exactly.

Assumptions

  • Adults; the boundaries were studied in adults.
  • This is a screening measure, not a diagnosis.

Worked examples by hand

34 in waist, 5 ft 8 in tall. 34 ÷ 68 = 0.500: increased risk (the boundary counts as 0.5 or more). Waist at 0.5 = 68 ÷ 2 = 34.0 in.

80 cm waist, 175 cm tall. 80 ÷ 175 = 0.457: no increased risk. Waist at 0.5 = 87.5 cm.

37.8 in waist, 5 ft 3 in tall. 37.8 ÷ 63 = 0.600: very high risk (0.6 counts as 0.6 or more).

Other questions people ask

How do I calculate my waist to height ratio?

Divide your waist by your height, both in the same unit. A 34 in waist at 68 in (5 ft 8 in) gives 34 ÷ 68 = 0.5.

What is a good waist to height ratio?

Below 0.5. Ashwell and Gibson (BMJ Open, 2016) used three groups: below 0.5 for no increased risk, 0.5 up to 0.6 for increased risk, and 0.6 or more for very high risk.

What does “keep your waist to less than half your height” mean?

It is the 0.5 boundary in plain words. If you are 175 cm tall, keep your waist below 87.5 cm; at 5 ft 8 in, below 34 in. The page shows this limit as “Waist at a ratio of 0.5”.

Is the waist to height ratio better than BMI?

Ashwell and Gibson found that a single 0.5 boundary for waist-to-height ratio picked out more people at early health risk than a matrix of BMI and waist circumference, including some with a healthy BMI. It is a quick screen, not a diagnosis.

Does the 0.5 boundary work for men and women?

Yes. The same boundary is used for adult men and women, which is one reason it is simple to use. Height already scales the waist to body size.

How should I measure my waist?

Stand relaxed, breathe out gently, and measure midway between your lowest rib and the top of your hip bone with the tape level and snug. Measure your height without shoes.