Body Measurement Tracker

Record five measurements and get three different readings from them: a Body Mass Index, a waist-to-hip ratio with a risk band, and a body shape classification with styling notes for that shape. Nothing is stored on a server, and nothing leaves the page.

Five Inputs, Three Separate Readings

These three measures answer different questions and none of them substitutes for the others. BMI asks whether your weight is unusual for your height, using no information about where that weight sits. The waist-to-hip ratio asks specifically about distribution, which is the component more closely tied to metabolic risk. The shape classification asks neither of those things — it is a description of proportion, intended for clothing and proportion rather than health.

• BMI is weight in kilograms divided by height in metres squared. It uses only the first two fields, so bust, waist and hips have no effect on it.
• The waist-to-hip ratio is waist divided by hips, and the page applies different thresholds depending on which gender you selected.
• The shape classification uses all three circumference measurements together, and its thresholds are also gender-specific.
• The page converts height to inches and shows it alongside centimetres, and positions your BMI on a bar spanning the range from 15 to 40.

Measuring So the Numbers Mean Something

1. Select Women or Men first. It changes the waist-to-hip thresholds and switches to a different set of shape rules, so a reading taken under the wrong setting is not comparable.
2. Measure height without shoes, standing against a wall with heels together. Record it in centimetres.
3. Weigh yourself at a consistent time of day. First thing in the morning before eating is the most reproducible, and consistency matters more than absolute accuracy.
4. Measure the waist at its narrowest point, usually just above the navel, without pulling the tape tight or holding your breath.
5. Measure the hips at the widest point of the seat, keeping the tape level all the way round — this is the measurement most often taken with the tape sloping.
6. Measure the bust at the fullest point. Record the date if you are tracking over time; a single reading is far less useful than a series.

A Worked Reading and the Rules Behind the Shape

Enter 165 cm, 60 kg, bust 90, waist 70 and hips 95 under the Women setting and the page returns a BMI of 22.0 in the Normal band, a waist-to-hip ratio of 0.74 marked as low health risk, and a classification of Hourglass. The BMI marker sits at 28 percent along its bar, because the bar spans 15 to 40 rather than starting at zero.

• Hourglass is assigned when the bust and hips are within 5 cm of each other and the waist is at least 15 cm smaller than the smaller of the two. In this example those are 5 and 20, so both conditions hold.
• Pear or Triangle is assigned when the hips exceed the bust by more than 5 cm, whatever the waist measures.
• Inverted Triangle is assigned when the bust exceeds the hips by more than 5 cm and the waist is more than 10 cm below the bust.
• Apple or Round is assigned when the waist is within 8 cm of both the bust and the hips, which describes a straighter silhouette.
• Anything left over is classified as Rectangle or Straight.
• Under the Men setting the rules differ. A chest-to-waist difference of 15 cm or more with hips narrower than the chest gives Athletic or V-shape; hips wider than the chest by more than 3 cm gives Pear; a waist within 5 cm of the chest gives Oval or Apple; the remainder is Rectangle. There is no Hourglass outcome at all, which is intentional rather than an omission.

What Each Reading Cannot Tell You

All three are ratios derived from a tape measure, and all three inherit the limitations of that.

• BMI cannot distinguish muscle from fat. Two people with identical readings can have very different body compositions, and the index is silent about which is which.
• The size of the tape error is comparable to the size of the effect you are looking for. A centimetre out on the waist changes the ratio by about 0.01, which is meaningful against a 0.05 threshold. Measure twice and record the second reading.
• The waist-to-hip thresholds are population-level tools. They identify where risk rises across a group; applied to one person on one day they are indicative rather than diagnostic.
• The shape classification is a description of proportion, not a health measure and not a standard. Different sizing systems and different retailers use different versions of these categories, so treat the output as a starting point for what to try on rather than a fixed identity.
• Body shape changes with weight, pregnancy and age, and the classification will change with it. That is expected behaviour, not a sign the earlier reading was wrong.

What to Add if You Want a Fuller Picture

Alternative	Notes
Waist-to-height ratio	Waist divided by height, with 0.5 as the widely used threshold. Needs one number you already have, and research suggests it tracks central fat at least as well as BMI does.
Trend rather than snapshot	The single most informative thing you can do with these fields over time. Compare measurements taken the same way, at the same time of day, months apart.
Body fat percentage	The measurement BMI is often mistaken for. Needs callipers, an impedance scale or a scan — none of which a browser can supply, which is why it is not in the form.
Chest, arm and thigh measurements	Useful if you are training, because they show where a change happened. A stable weight with a shrinking waist and a growing arm is a very different result from a stable weight alone.

Measurement Questions

Which of the three readings is the most useful?

For health purposes, the waist-to-hip ratio generally carries more information than BMI, because distribution matters more than total weight. For practical purposes, the shape classification is the one most people actually use, since it maps directly onto what fits. There is no single right answer — they answer different questions, which is why the page shows all three rather than collapsing them into a score.

Why are the thresholds different for women and men?

Because the underlying risk relationship differs. Women carry more of their fat subcutaneously and men more viscerally at the same waist-to-hip ratio, so the point at which risk rises differs too. The shape rules differ for a related reason — the categories people use for clothing are defined differently for each.

Is my data saved or sent anywhere?

No. The calculations run entirely in the page and the form does not submit anywhere. Nothing is written to storage and nothing is transmitted, so closing the tab discards everything. If you want a record, note the figures down or take a screenshot.

Can I use this to track a child's growth?

No. BMI bands for children and adolescents depend on age and sex percentiles from growth charts, and the adult bands applied to a growing child give misleading results in both directions. The shape classification is also not meaningful during growth.

Last verified: October 3, 2026

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Maintained by Huang Bin · Last updated October 3, 2026