Educational measurement tool

Cun Measurement Converter

Static B-cun reference table

Landmark span	B-cun	Use in this tool
Body height	75	Educational whole-body proportional estimate
Anterior hairline to posterior hairline	12	Head reference span
Sternal angle to umbilicus	8	Anterior trunk reference span
Umbilicus to pubic symphysis	5	Lower abdomen reference span
Axillary fold to cubital crease	9	Upper arm reference span
Cubital crease to wrist crease	12	Forearm reference span
Greater trochanter to popliteal crease	19	Lateral thigh reference span
Popliteal crease to lateral malleolus	16	Lower leg reference span

Point pages using cun-based location statements

LU-1 ZhōngfǔOn the upper anterior chest, level with the first intercostal space and 6 B-cun lateral to the anterior midline; it lies 1 B-cun below LU-2.LU-2 YúnménIn the infraclavicular fossa, medial to the coracoid process and 6 B-cun lateral to the anterior midline.LU-3 TiānfǔOn the anterolateral upper arm, just lateral to the biceps brachii border and 3 B-cun below the anterior axillary fold.LU-4 XiábáiOn the anterolateral upper arm, just lateral to the biceps brachii border and 4 B-cun below the anterior axillary fold.LU-6 KǒngzuìOn the anterolateral forearm, on the line from LU-5 to LU-9 and 7 B-cun above the palmar wrist crease.LU-7 LièquēOn the radial forearm, between the abductor pollicis longus and extensor pollicis brevis tendons, 1.5 B-cun above the palmar wrist crease.LU-8 JīngqúOn the anterolateral forearm, between the radial styloid process and radial artery, 1 B-cun above the palmar wrist crease.LU-11 ShàoshāngOn the radial side of the thumb's distal phalanx, 0.1 f-cun proximal-lateral to the radial corner of the thumbnail.LI-1 ShāngyángOn the radial side of the index finger, 0.1 finger-cun proximal and lateral to the radial corner of the nail.LI-6 PiānlìOn the posterolateral forearm, on the line from LI-5 to LI-11 and 3 body-cun above the dorsal wrist crease.LI-7 WēnliūOn the posterolateral forearm, on the line joining LI-5 and LI-11 and 5 body-cun above the dorsal wrist crease.LI-8 XiàliánOn the posterolateral forearm along the LI-5 to LI-11 line, 4 body-cun below the cubital crease.

Frequently asked questions

What is a B-cun?

B-cun is a proportional bone measurement used to describe relative anatomical distances. It is not a fixed universal centimetre value.

How does this converter work?

It divides the landmark length you enter by the traditional B-cun count assigned to that span, then displays common multiples.

How many cun is three finger widths?

Finger-width methods are approximate and depend on the patient’s own hand. A commonly taught reference treats four fingers together as about 3 cun, but proportional bone landmarks are preferred when available.

Is one cun the same for every body area?

No. Proportional values are derived from the selected anatomical span, so the centimetre result can differ by region and person.

Can this tool locate a point for self-needling?

No. It is an educational conversion aid and cannot replace anatomy, palpation, supervised training, or individualized assessment.

Does the tool recommend acupuncture treatment?

No. It only performs arithmetic using the length and landmark count you select.

Sources

References displayed on this page were recorded with the point dataset.