Type your waist and your height. You get your waist-to-height ratio, the band NICE puts it in, how far your waist is from half your height — the line NICE and the NHS give — and how NICE says to measure. It informs; it is not a diagnosis.
Waist 30 in, height 5 ft 5 in (165.1 cm)
0.46 · under 0.5 — under half your heightYour waist is 46% of your height. NICE: “healthy central adiposity: waist-to-height ratio 0.4 to 0.49, indicating no increased health risks.” NICE and the NHS write it for adults with a BMI under 35. It is one measure among several — your doctor reads it with the rest.
- Ratio
- 0.46
- Waist
- 30 in (76.2 cm)
- Height
- 5 ft 5 in (165.1 cm)
- Half your height
- 32.5 in
Half your height is 32.5 in; your waist is 2.5 in under it. A ratio of 0.6 would be a 39 in waist.
Your waist-to-hip ratio too: open the Waist-to-Hip Ratio Calculator with this waist
On Needle Style: outfits for broad shoulders and wide hips · outfits for broad shoulders and a large bust · jeans that fit at the waist
Bands and the half-your-height line from NICE guideline NG246 (updated 8 January 2026) and the NHS (reviewed 29 April 2026); how to measure from NICE. Checked 2026-10-10. Where a ratio sits on a band’s edge is ours.
Quick answer: your waist-to-height ratio is your waist divided by your height, both in the same unit — a 30 in waist at 5 ft 5 in (65 in) is 0.46. NICE and the NHS give one line: keep your waist to less than half your height, a ratio under 0.5. NICE’s next bands are 0.5 to 0.59 and 0.6 or more. It informs; it is not a diagnosis.
How to use it
Measure your waist the way NICE does (below), and type it with your height — feet and inches (5’5) or inches (65), or centimetres. You get the ratio, the band NICE puts it in, how far your waist is from half your height, and a link that opens our Waist-to-Hip Ratio Calculator with the same waist.
NICE’s bands, in NICE’s words
NICE guideline NG246 classifies the ratio in three bands: “healthy central adiposity: waist-to-height ratio 0.4 to 0.49, indicating no increased health risks”, “increased central adiposity: waist-to-height ratio 0.5 to 0.59, indicating increased health risks” and “high central adiposity: waist-to-height ratio 0.6 or more, indicating further increased health risks.” It adds: “The health risks associated with higher levels of central adiposity include type 2 diabetes, hypertension and cardiovascular disease.” And the one line to remember: “When talking to a person about their waist-to-height ratio, explain that they should try and keep their waist to less than half their height (so a waist-to-height ratio of under 0.5).”
The NHS says the same: “You should try to keep your waist size to less than half your height.” Both write it for adults with a BMI under 35 — NICE: “These classifications can be used for people with a BMI under 35 … of both sexes and all ethnicities, including adults with high muscle mass.”
What is ours: a ratio exactly on 0.5 or 0.6 sits in the band that starts there (NICE writes “0.5 to 0.59” and “0.6 or more”); anything under 0.5 is under 0.5, as NICE’s line says; NICE lists no band under 0.4, and the calculator says so instead of naming one; and the check that a height is 3 to 8 feet and a waist 15 to 100 inches.
Half your height, by height
The waist that is exactly half your height (a ratio of 0.5) and the waist at 0.6, for each height.
| Height | Waist at 0.5 (half) | Waist at 0.6 |
|---|---|---|
| 4 ft 10 in (147.3 cm) | 29 in (73.7 cm) | 34.8 in (88.4 cm) |
| 5 ft 0 in (152.4 cm) | 30 in (76.2 cm) | 36 in (91.4 cm) |
| 5 ft 2 in (157.5 cm) | 31 in (78.7 cm) | 37.2 in (94.5 cm) |
| 5 ft 4 in (162.6 cm) | 32 in (81.3 cm) | 38.4 in (97.5 cm) |
| 5 ft 6 in (167.6 cm) | 33 in (83.8 cm) | 39.6 in (100.6 cm) |
| 5 ft 8 in (172.7 cm) | 34 in (86.4 cm) | 40.8 in (103.6 cm) |
| 5 ft 10 in (177.8 cm) | 35 in (88.9 cm) | 42 in (106.7 cm) |
| 6 ft 0 in (182.9 cm) | 36 in (91.4 cm) | 43.2 in (109.7 cm) |
| 6 ft 2 in (188 cm) | 37 in (94 cm) | 44.4 in (112.8 cm) |
| 6 ft 4 in (193 cm) | 38 in (96.5 cm) | 45.6 in (115.8 cm) |
How NICE says to measure
- “Find the bottom of the ribs and the top of the hips. Wrap a tape measure around the waist midway between these points (this will be just above the belly button) and breathe out naturally before taking the measurement.”
- “Measure waist circumference and height in the same units (either both in centimetres, or both in inches).”
- “If you know your height in feet and inches, convert it to inches (for example, 5 feet 7 inches is 67 inches).”
Worked examples
- A 30 in waist at 5 ft 5 in: 0.46 · under 0.5 — under half your height. Half your height is 32.5 in; the waist is 2.5 in under it.
- NICE’s own example, 38 in at 5 ft 7 in (67 in): 0.57 · NICE’s 0.5 to 0.59 band — “38 inches divided by 67 inches = waist-to-height ratio of 0.57 or 96.5 cm divided by 170 cm = waist-to-height ratio of 0.57.”
- The same body in centimetres, 96.5 cm at 170 cm: 0.57 · NICE’s 0.5 to 0.59 band. Inches or centimetres give the same ratio, as long as both are the same unit.
- A 32.4 in waist at 5 ft 5 in: 0.498 · under 0.5 — under half your height. Two decimals would round it to 0.50, so the calculator shows three.
Common mistakes
- Mixing units. A waist in inches over a height in centimetres gives a meaningless number.
- Typing 5.5 for 5 ft 5 in. 5.5 feet is 5 ft 6 in; type 5’5 or 65.
- Measuring at the narrowest point or holding your breath. NICE measures midway between the ribs and the hips, after a natural breath out.
- Reading it as a verdict. It is one measure among several; a doctor reads it with the rest.
Frequently asked questions
How do you calculate waist to height ratio?
Divide your waist by your height, both in the same unit. A 30 in waist and a 65 in height (5 ft 5 in): 30 ÷ 65 = 0.46.
What is a good waist to height ratio?
NICE and the NHS give one line: keep your waist to less than half your height, a ratio under 0.5. NICE’s bands above it are 0.5 to 0.59 and 0.6 or more. Under 0.5 is under that line — not a clean bill of health, which only a doctor can give.
Is the waist to height ratio the same for men and women?
Yes. NICE: the bands “can be used for people with a BMI under 35 … of both sexes and all ethnicities, including adults with high muscle mass.”
Where do I measure my waist?
“Find the bottom of the ribs and the top of the hips. Wrap a tape measure around the waist midway between these points (this will be just above the belly button) and breathe out naturally before taking the measurement.” (NICE).
Waist to hip or waist to height — which should I use?
They measure different things. NICE and the NHS use waist-to-height; WHO’s cut-offs are for waist-to-hip. Our Waist-to-Hip Ratio Calculator opens with your waist from here.
On Needle Style
Dressing your proportions: outfits for broad shoulders and wide hips, outfits for broad shoulders and a large bust and jeans that fit at the waist.
More free tools: the waist-to-hip ratio calculator, the body shape calculator and the women’s size converter.