Calculator · Health
Waist to Height Ratio Calculator
Your waist to height ratio (WHtR) is your waist measurement divided by your height. The simple rule from UK health guidance: keep your waist to less than half your height. Enter two numbers below to see your ratio, what it means and the waist size that matches 0.5 for your height.
Your waist to height ratio
Health bands from NICE (UK) guidance for adults with a BMI under 35. A screening tool, not a diagnosis.
What is waist to height ratio?
Waist to height ratio, or WHtR, compares the size of your waist with your height. It’s a quick way to estimate how much fat you carry around your middle, which is the fat most closely linked to type 2 diabetes, heart disease and high blood pressure.
Because it scales with height, the same cut-offs work for men and women and for tall and short people. That’s why UK health guidance from NICE, introduced in 2022, recommends that adults keep their waist to less than half their height.
How to calculate waist to height ratio
Waist to height ratio = waist ÷ height
Example: 34 in ÷ 70 in (5 ft 10) = 0.49
Use the same unit for both numbers: inches with inches, or centimetres with centimetres. To turn feet into inches, multiply the feet by 12 and add the remaining inches (5 ft 10 in = 60 + 10 = 70 in). The calculator above does this for you.
How to measure for waist to height ratio
- Height: stand barefoot against a wall, heels together, and mark the top of your head with a flat object. Measure from the floor to the mark.
- Find your waist: locate your lowest rib and the top of your hip bone at the side. Your waist is halfway between them; for most people this is close to the belly button.
- Measure: wrap a soft tape around your body at that point, level all the way round. Breathe out normally and read the tape without pulling it tight.
- Repeat: take two measurements and use the average.
Healthy waist to height ratio range
| Ratio | What it means (NICE) |
|---|---|
| 0.40–0.49 | No increased health risk |
| 0.50–0.59 | Increased health risk |
| 0.60 and above | High health risk |
These bands are the same for men and women, and NICE recommends them for adults with a BMI under 35. A ratio below 0.4 isn’t a risk band in the guidance, but it can go with low body weight; if that applies to you, check your BMI and talk to a doctor if you’re concerned.
A high ratio is a reason to speak to a doctor, not a diagnosis. It doesn’t account for pregnancy, and it’s less reliable for children, whose ratio should be assessed by a health professional.
Waist to height ratio chart
Find your height to see the waist size at each boundary. A waist smaller than the 0.5 figure for your height is in the range NICE describes as no increased health risk.
| Height | 0.4 | 0.5 | 0.6 |
|---|
Waist to height ratio vs BMI and waist to hip ratio
| Measure | What it uses | Strength | Weak spot |
|---|---|---|---|
| BMI | Weight and height | Simple, widely used | Can’t tell muscle from fat or show where fat sits |
| Waist to height ratio | Waist and height | Shows fat around the middle; one cut-off (0.5) for everyone | Needs a careful waist measurement |
| Waist to hip ratio | Waist and hips | Shows where you store fat | Different cut-offs for men and women; ignores height |
Research reviews have found waist to height ratio predicts heart and metabolic risk better than BMI, which is why NICE now recommends using it alongside BMI rather than BMI alone.
Army and Air Force waist to height ratio standard
The US military now uses waist to height ratio for body composition checks:
- US Army: a ratio under 0.55 meets the standard. The Army adopted it in July 2026, measuring the waist at the navel.
- US Air Force and Space Force: also under 0.55, assessed since April 2023, with the waist measured midway between the lowest rib and the top of the hip bone.
The calculator above shows whether your ratio is under 0.55. Official assessments follow each service’s own procedure, so use this as a practice check only.
Frequently asked questions
How do you calculate waist to height ratio?
Divide your waist measurement by your height, using the same unit for both. For example, a 32-inch waist and a height of 5 ft 6 in (66 inches) gives 32 ÷ 66 = 0.48.
What is a healthy waist to height ratio?
Between 0.4 and 0.49, according to NICE guidance in the UK. In other words, your waist should be less than half your height. The same range applies to men and women.
Where do you measure your waist for waist to height ratio?
Halfway between your lowest rib and the top of your hip bone, which is close to the belly button for most people. Breathe out normally and keep the tape level and snug, not tight.
Is waist to height ratio better than BMI?
For spotting health risk, studies suggest it often is, because it reflects fat around the middle while BMI only uses weight and height. Doctors increasingly use the two together.
What is the Army waist to height ratio standard?
The US Army requires a waist to height ratio under 0.55, measured at the navel. The Air Force and Space Force also use under 0.55.
Related tools
This calculator is for general information and screening only. It doesn’t diagnose any condition or replace advice from a doctor. See our disclaimer.