For the location of acupuncture points, measurement units such as centimeters or inches cannot be used because there are many size differences between human beings. Therefore, anatomical references (bones, tendons) and proportional measurements or cun are used.

Each part of the body is considered to have certain cun or distances and you find the points proportionally.

It is taken as reference that 1 cun is the width of the thumb of the hand. But this distance is not valid for the entire body: the distances of the different areas must be known to correctly locate the points. For a quick example: from the umbilicus to the upper border of the pubic symphysis there are 5 cun. Is 5 times the width of your thumb enough to cover that distance?

It should also be noted that the patient's cun must be used as reference, not the acupuncturist's, to locate the points.

Hand

• 1 cun: width of the thumb or the length of the middle phalanx of the middle finger.
• 1.5 cun: width of the index and middle fingers together.
• 2 cun: width of the index, middle and ring fingers together.
• 3 cun: width of the index, middle, ring and little fingers together.

Upper limb

• Forearm, from the wrist crease to the elbow there are 12 cun.
• From the elbow crease to the end of the axillary crease there are 9 cun.

Lower limb

Thigh:

• From the upper border of the pubic symphysis to the upper border of the patella there are 18 cun.
• From the upper border of the greater trochanter of the femur to the popliteal crease there are 19 cun.
• At the back, from the gluteal crease to the popliteal crease: 14 cun.
• Height of the patella: 2 cun.

Leg:

• From the lower border of the patella to the tip of the malleolus there are 16 cun.

Chest and abdomen

• From nipple to nipple: 8 cun.
• Height from the umbilicus to the costal margin (not to be confused with the xiphoid process): 8 cun.
• Height from the umbilicus to the pubic symphysis: 5 cun.
• Width from the umbilicus to the lateral waist: 6 cun.
• Lateral height, from the end of the axillary fold to the last rib: 12 cun.

Back

From the center of the spine to the inner border of the scapula: 3 cun.

Head

• From the anterior hairline to the posterior hairline: 12 cun.
• From corner to corner of the forehead (ST-8): 9 cun.
• From the center of the eyebrows to the anterior hairline: 3 cun.