Waist-to-Hip Ratio Calculator
This waist to hip ratio calculator divides your waist measurement by your hip measurement and reads the answer against the two lines that the WHO’s 2008 report uses as examples — 0.90 for men and 0.85 for women — plus the 1.00 line that the same report describes as substantially increased risk for both sexes. It answers a shape question rather than a weight question: the number tells you where your body stores fat (an apple or a pear pattern), not how much of it you carry. The card opens on a preset of 85 cm and 95 cm for a male, which returns a headline of 0.89 and the badge “Within the WHO reference line”, so there is a complete result on screen before you type anything.
Measurements
Waist-to-hip ratio
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Measure the hip at its widest point (not the hip bone) and the waist at the narrowest point of the torso. Keep the tape level and snug, but not tight.
What the Waist to Hip Ratio Actually Measures
The waist to hip ratio — often written waist hip ratio, and abbreviated WHR — is one division: your waist circumference divided by your hip circumference. It is a shape measurement, and it answers a question a scale cannot: when your body stores fat, does it put more of it around the middle (the apple pattern) or around the hips and thighs (the pear pattern)? A higher ratio means more of the fat sits on the trunk; a lower one means more of it sits below the waist. The WHR calculator reduces that shape to a single number you can track over time, and because both measurements are lengths, the ratio itself has no unit — centimetres divided by centimetres and inches divided by inches return the same figure.
The reason a tape measurement earns a card of its own is that body fat is not stored uniformly. The fat around the abdomen — the depot the waist captures — is the more metabolically active kind, and it is the one the WHO’s analysis ties to metabolic and cardiovascular risk; fat carried on the hips and thighs behaves differently. Two people of the same weight can therefore hold the same amount of fat in places that do not mean the same thing. The body mass index cannot see that difference, because it divides weight by height squared and never looks at where the weight sits; a tape-based ratio can. That is the whole case for measuring the waist and the hips, and the whole reason the two numbers are divided rather than reported bare.
Screening, not diagnosis — and the measurement is half the result. A ratio describes a population pattern, and a band describes where your number falls in that pattern; it does not name a condition and it does not prescribe anything. The other half is the tape work: a waist measured over clothing, or a tape pulled tight enough to compress the skin, can move the result more than a real change in body shape. Measure bare skin (or light clothing), keep the tape level all the way around, and read each site the same way every time. The measurement technique is described step by step in the how-to section below.
The Waist to Hip Ratio Formula and the WHO Reference Lines
The waist to hip ratio formula is one division long, and everything else on the card is derived from it:
\[ \text{WHR} = \frac{\text{waist}}{\text{hip}} \]
where both circumferences are measured in the same unit. The tool converts everything to centimetres first — the metric and imperial branches of a circumference formula are not interchangeable, so there is a single conversion point — which means an inch tape and a centimetre tape produce one result:
\[ 1\ \text{in} = 2.54\ \text{cm}, \qquad \text{waist in cm} = \text{waist in inches} \times 2.54 \]
Your sex selects the reference line the result is read against, and the card prints the signed distance from your ratio to that line:
\[ \text{Reference line} = \begin{cases} 0.90 & \text{men} \\ 0.85 & \text{women} \end{cases}, \qquad \text{Ratio vs that line} = \text{WHR} – \text{reference line} \]
A word on where those two numbers come from, because the card is deliberately careful about it. They are the reference lines used in the WHO’s 2008 expert consultation report on waist circumference and waist-to-hip ratio, and the report itself notes that they are example values rather than a formal cut-off — the evidence across populations was not consistent enough to fix a single threshold. They are still the lines the field most often quotes, which is why this calculator prints them, but it prints the caveat next to them: “an example value in the WHO report, not a formal cut-off”. The one line the report states positively is 1.00, and that line is the same for both sexes:
\[ \text{WHR} > 1.00 \quad \Rightarrow \quad \text{substantially increased risk for both sexes} \]
A table of the symbols the card uses, and how each one is produced:
| Symbol | Meaning | How it is used |
|---|---|---|
| WHR | waist-to-hip ratio | the headline reading, waist ÷ hips |
| W | waist circumference | entered in centimetres or inches, converted to centimetres |
| Hip | hip circumference | entered in the same unit as the waist, converted to centimetres |
| Line | WHO reference line for the selected sex | 0.90 for men, 0.85 for women — an example value in the WHO report, not a formal cut-off |
| Diff | ratio vs that line | WHR − Line, signed: + above, − below, ± exactly on the line |
Here is the waist to hip ratio chart the badge is drawn from, in the three bands exactly as the card words them:
| Badge (card text) | Ratio | What it describes |
|---|---|---|
| Within the WHO reference line | 0.90 or below (men) / 0.85 or below (women) | at or under the example line for the selected sex |
| Above the WHO line (central obesity) | above 0.90 up to 1.00 (men) / above 0.85 up to 1.00 (women) | above the reference line — the apple pattern the ratio is designed to flag |
| Substantially increased risk | above 1.00 | the one line the WHO report states for both sexes |
Precision and boundaries. Only positive numbers are accepted, and each tape field has a wide sanity range: the waist must be 30 to 250 cm (12 to 98 in) and the hips 50 to 250 cm (20 to 98 in). Results are rounded for display: the headline is rounded to two decimals, the equation line keeps three, and the reference line and the signed difference keep two. The Waist and Hip rows keep at most one decimal, so 85 cm stays 85 cm and 87.5 cm would print with its 87.5 intact — trailing zeros are dropped on those two rows. When a value cannot be used, the card keeps the previous result on screen and adds one line naming the reason: “Please enter a valid number.” for a blank or non-numeric field; “Waist is out of range — enter 30 to 250 cm (12 to 98 in).” when the waist falls outside its range; and “Hip is out of range — enter 50 to 250 cm (20 to 98 in).” when the hip does.
How to Use the Waist-to-Hip Ratio Calculator
- Pick the unit system first. Metric reads centimetres; imperial reads inches. Switching units converts the values already typed — the 85 cm preset becomes 33.5 in — so a metric figure cannot silently turn into an absurd inch one.
- Choose your sex. This is not a label: it selects the reference line (0.90 for men, 0.85 for women), so the same tape numbers can land in different bands under the two settings.
- Measure your waist. At the narrowest point of your torso, or level with your navel if that is easier to find — measured after a normal exhale, with the tape level all the way around and snug but not compressing the skin.
- Measure your hips. At the widest point, around the fullest part of the buttocks. Take each site twice and keep the routine identical; a consistent routine matters more than any single reading.
- Read the headline and the equation line. The headline is the ratio to two decimals — the number the bands are read against — while the equation line keeps three, which is where you can see that 85 ÷ 95 is not 0.89 exactly.
- Read the rows. Waist, Hip, WHO reference line (this sex), Ratio vs that line, Category and the Substantially increased risk line. The WHO row carries its own caveat, and the Ratio row carries the sign (+ above, − below, ± on the line).
- Take the result with you. The copy buttons hand you the headline alone or the full summary line, and the card can be exported as an image or a PDF — the QR code in the file encodes this page together with your inputs, so scanning it reopens the calculator with the same numbers filled in.
Worked Examples
The three examples below are metric cards, quoted row for row from what the tool prints. The first is the preset the page loads with, so it is also the quickest way to see what the rows are called.
Example 1 — a man, 85 cm waist and 95 cm hip (the default preset)
The preset card returns the headline 0.89 with the equation line “85 cm ÷ 95 cm = 0.895” — the headline keeps two decimals, the equation three, and this division is exactly the case where the third decimal is informative. The rows below the headline read: Waist “85 cm”; Hip “95 cm”; WHO reference line (this sex) “0.90 — an example value in the WHO report, not a formal cut-off”; Ratio vs that line “−0.01”; Category “Within the WHO reference line”; Substantially increased risk “above 1.00 — for both sexes”. The badge is “Within the WHO reference line”, and the summary line the copy button hands you is: “Waist-to-hip ratio 0.89 (Within the WHO reference line) — 0.01 below the WHO reference line of 0.90”. On an inch tape this is about 33.5 in ÷ 37.4 in, which returns the same 0.89, because the ratio is unitless.
Example 2 — a man, 95 cm waist and 100 cm hip
Keep the same sex and move the waist past the reference line: 95 cm and 100 cm. The headline is 0.95 and the equation line reads “95 cm ÷ 100 cm = 0.950” — the third decimal is a trailing zero this time, shown because the equation row always keeps three decimals. Ratio vs that line now reads “+0.05”, the Category and the badge read “Above the WHO line (central obesity)”, and the Substantially increased risk row still reads “above 1.00 — for both sexes”, which is the line that does not depend on sex. The summary line is: “Waist-to-hip ratio 0.95 (Above the WHO line (central obesity)) — 0.05 above the WHO reference line of 0.90”. Note the wording of the middle band: at 0.95 the ratio is above the reference line but not yet past 1.00, so the card names the pattern (central obesity) without calling it substantially increased risk.
Example 3 — a woman, 80 cm waist and 90 cm hip
The third example changes sex, and that changes everything about how the same reading is judged. Waist 80 cm, hip 90 cm, female. The headline is 0.89 — identical to Example 1 — but the equation line reads “80 cm ÷ 90 cm = 0.889”, and because the reference line for women is 0.85, the verdict flips: Ratio vs that line “+0.04”; Category “Above the WHO line (central obesity)”; WHO reference line (this sex) “0.85 — an example value in the WHO report, not a formal cut-off”. The summary line is: “Waist-to-hip ratio 0.89 (Above the WHO line (central obesity)) — 0.04 above the WHO reference line of 0.85”. Put Example 1 and Example 3 side by side and the lesson is visible: 0.89 sits within the reference line for a man and above it for a woman, so the sex input is not decoration — it decides which line the result is read against.
| Card | Headline | Equation | Ratio vs that line | Badge |
|---|---|---|---|---|
| Man — waist 85 cm, hip 95 cm | 0.89 | 85 cm ÷ 95 cm = 0.895 | −0.01 | Within the WHO reference line |
| Man — waist 95 cm, hip 100 cm | 0.95 | 95 cm ÷ 100 cm = 0.950 | +0.05 | Above the WHO line (central obesity) |
| Woman — waist 80 cm, hip 90 cm | 0.89 | 80 cm ÷ 90 cm = 0.889 | +0.04 | Above the WHO line (central obesity) |
Waist-to-Hip Ratio FAQ
What is a healthy waist to hip ratio?
On this card, a healthy waist to hip ratio is 0.90 or below for men and 0.85 or below for women — the readings the badge labels “Within the WHO reference line”. Above the line for your sex the card reads “Above the WHO line (central obesity)”, and above 1.00 it reads “Substantially increased risk”. Keep the framing honest: the two sex-specific numbers are example values in the WHO’s 2008 report rather than formal cut-offs, and the 1.00 line is the one the report states positively for both sexes. A reading near a line is a prompt to look at the whole picture, not a verdict on its own.
How do I measure my waist and hips for this ratio?
Measure your waist at its narrowest point — or level with your navel if that is easier to find — and your hips at the widest point, keeping the tape level all the way around and snug without compressing the skin. Take both after a normal exhale rather than a forced one, measure each site twice, and keep the routine identical every time. One or two centimetres of sloppy tape work is enough to move a reading across a reference line, so the technique is not a formality — it is half of the result.
Does the waist to hip ratio calculator work in inches?
Yes. Switch the unit toggle to imperial and the waist and hip fields are read in inches, with both values converted to centimetres before the division, so the ratio itself is identical to the metric version. Switching units also converts the numbers already typed: the 85 cm preset becomes 33.5 in, and the 95 cm hip becomes 37.4 in, which returns the same headline and the same badge. Nothing is silently reinterpreted, so a figure entered in centimetres cannot turn into a mismatched inch value.
What does the “Ratio vs that line” row mean?
It is the signed gap between your ratio and the reference line for your sex, printed to two decimals. A plus sign means you are above the line and a minus sign means you are below it: “−0.01” when a ratio of 0.89 sits just under the men’s line of 0.90, “+0.05” when a ratio of 0.95 sits just above it, and “±0.00” if the ratio lands exactly on the line. The row carries the same two-decimal precision as the headline, so it is the quickest way to see how far off the line you are, not just which side.
Is the waist-to-hip ratio a diagnosis?
No. It is a screening ratio that describes where your body stores fat, and every band the card prints is a reference range rather than a medical conclusion. The number cannot measure fat directly, it says nothing about fitness or muscle, and a single reading on a single day is affected by the tape as much as by your body. If a reading concerns you — especially one above 1.00, the line the WHO report states positively — take it to a clinician as one piece of evidence rather than reading it as an answer, and track the trend over weeks instead of reacting to one measurement.
What about the 0.7 waist to hip ratio quoted online?
The 0.7 figure comes from research on perceived attractiveness, not from health screening. Studies of how people rate women’s body shapes, such as Singh’s work in the 1990s, found ratios around 0.7 were rated highly — but that is a perception finding, not a health line. Figures such as 0.6, 0.7 and 0.75 circulate in that literature and in fashion writing; they describe what observers find attractive, not what a screening tool measures. The health-relevant lines used here are the WHO’s example values (0.90 for men, 0.85 for women) and the 1.00 substantially-increased-risk line, and those three are the ones the card prints.
Why are the lines different for men and women?
Because the same ratio sits on different bodies: women on average carry more fat on the hips and thighs, men more on the abdomen. A single dividing line therefore cannot describe both — the pear pattern and the apple pattern are not the same storage site. The card uses the sex input to pick the line — 0.90 for men, 0.85 for women — and this is exactly why the same headline of 0.89 reads “Within the WHO reference line” in Example 1 and “Above the WHO line (central obesity)” in Example 3. Only the 1.00 line is shared by both sexes.
Related Tools
The pages around this one take the same tape and ask different questions. The waist-to-height ratio calculator divides the waist by your height instead of your hips and checks the result against the NICE bands — the better question when you want to know whether the waist is large for your frame rather than where the fat sits. The Navy body fat calculator turns neck, waist and hips into an estimated body fat percentage with the Hodgdon and Beckett regression, which is the measurement to reach for if the shape reading makes you want a composition number. And the enhanced BMI calculator prints a BMI with both the WHO and Asian-Pacific categories plus a waist-to-height line, for the weight-for-height picture that WHR deliberately does not answer. Read the three together and you have the tape covered from three angles: shape here, scale-independence next door, and composition one page over.
