Segmental Circumference
Body circumferences are estimates of the dimensions of eight sites — neck, chest, abdomen, hips, both arms and both thighs — derived from body composition.
Short answer
The circumferences on the result sheet are estimates rather than tape measurements, and the manual gives no reference range for them. Use them as a rough map of proportions and reach for a tape when you need exact numbers.
What the value represents
The device uses no tape measure for these values. The manual describes them as estimated circumferences of eight sites on the body, calculated from the body composition analysis.
The eight sites: neck, chest, abdomen, hips, right and left arm, right and left thigh. Sides are given from the point of view of the person being measured.
They are useful chiefly as a rough map of proportions and as a basis for following development. A specific centimetre figure will not match what you measure with a tape.
The manual gives no reference range for these circumferences, and its example values are demonstrably corrupted, so not even a typical range can be read from them.
- Estimated circumferences of eight sites on the body, in centimetres.
- A description of proportions and how they develop over time.
- They do not represent the amount of fat or muscle at a given site; segmental lean mass and segmental fat serve that purpose.
How the value is produced
- An estimate from body composition. The manual gives no calculation method.
- Waist circumference is a separate value outside this group; with the Yscope module attached, a genuinely measured circumference is shown for it instead of an estimate. For these eight sites the manual gives no measured variant.
- Because the input is a body composition estimate, the circumferences inherit its uncertainty and its sensitivity to hydration.
How to read the current value
- The manual gives no reference range for these circumferences, so there is no value to compare them against.
- They are meaningful in comparison with themselves: left versus right, upper versus lower body, today versus last time.
- Read a difference between sides cautiously. A small difference is ordinary, and an estimate may not capture it reliably.
- If you need exact numbers, for clothing or rehabilitation for instance, measure the circumferences with a tape.
How to read change over time
- Follow the direction, not individual centimetres.
- Abdominal circumference moves hand in hand with waist circumference and visceral fat; limb circumferences move with the muscle and fat mass of that segment.
- Short-term changes mainly reflect variation in the body composition estimate, that is hydration, food and training.
General principles: how to read change between measurements →
What to read it with
- Segmental lean mass – what in a segment is lean tissue.
- Segmental fat – the fat component of the same segment.
- Waist circumference and the waist-hip ratio – indicators derived from trunk circumferences.
- Arm circumference and arm muscle circumference – a more detailed view of the upper limb.
- Weight – the context of overall change.
Common misunderstandings
- These are not tape measurements, even though the values are called circumferences.
- A circumference does not say how much of a given site is muscle and how much is fat.
- A difference between the right and left side need not mean asymmetry; it can be imprecision in the estimate.
- The manual gives no reference range for the circumferences, so there is no recommended neck or thigh circumference.
What can affect the result short term
- Hydration, food and drink before the measurement.
- Training shortly before the measurement.
- Bloating and bowel contents for abdominal circumference.
- Time of day and the shift of fluid towards the lower half of the body.
- The menstrual cycle.
What to do next
- If you are following your physique, keep your own tape measurements at two or three sites; they are more stable than an estimate.
- For assessing muscle, use segmental lean mass rather than circumferences.
- Follow abdominal circumference and waist circumference together; they are two different figures from the same result.
What the value does not determine
- This is not anthropometric measurement but an estimate from body composition.
- The manual gives neither a reference range nor the calculation method.
- They do not establish the split between muscle and fat at a given site.
- The manufacturer internal validation study against DEXA did not cover circumferences.
On terminology
- The group name describes a set of values on the result, not how they were obtained. The manual classes them among estimated values.
- Right and left are given from the point of view of the person being measured, not the observer.
In more depth, with sourcesIn more depth: where the circumferences come from and why they lack referencesExpand the detailed explanation
The manual describes segmental circumferences as estimated circumferences of eight sites on the body. The device measures impedance in five segments; a circumference cannot be derived directly from impedance without a modelling assumption about the shape of the segment. That is precisely why this is an estimate and why the manufacturer does not publish the calculation method.
For these values the source offers neither a reference range nor usable example values. The repository reference documents that the example table in the manual is corrupted — it contains figures such as a chest of 4.14 cm or a right arm of 3.41 cm, values copied from the body composition table. No typical span, let alone a threshold, can be derived from such material.
The manufacturer internal validation study against DEXA covered fat free mass, fat mass and segmental lean mass, not circumferences. The only published correlation for a circumference is the catalogue figure of R² 0.982 between waist circumference measured by the Yscope module and a tape measure — and that concerns the waist and only with Yscope connected.
The practical conclusion: use circumferences for a trend and for a rough comparison of symmetry, and read them alongside segmental lean mass and segmental fat, which are better documented for the same segment. Your own tape measurement is more dependable for absolute numbers.
Sources
- InBody 970 Result Sheet Interpretation (ENG_A_211104) — InBody Co., Ltd.
- Validation of InBody 970 (BWA) against DEXA — InBody Co., Ltd.
On this page
Related values
Related articles
Where to find it
The Visceral Fat Analysis, circumferences and basal metabolic rate.
- Reviewed by
- MojeInBody content team
- Date
An InBody measurement is not a diagnostic tool. Results do not determine health status and do not replace a medical examination.
FAQ
Frequently asked questions
Answers to what people ask most often about this value.
Why did I get a different thigh circumference from the one I measured with a tape?
Because the device does not measure the circumference but estimates it from body composition. A difference of several centimetres is therefore not an error in the device or in your tape.
What neck circumference is fine?
The manual gives no reference range for these circumferences, so the result sheet cannot answer that question. What makes sense is following your own development rather than comparing against a threshold.
Is a difference between the right and left side a problem?
A small difference is ordinary, and with estimated circumferences it can also be imprecision in the calculation. If symmetry interests you, look at segmental lean mass; the manual moreover gives no threshold differences for its balance evaluation.
Explanations make the most sense alongside your own trend.
The public guide is open to everyone. The client portal adds your own value, history and the context of a specific measurement.