Starting at a level below the umbilicus in the right mid-clavicular line, lightly percuss upward toward the liver. Ascertain the lower border of liver dullness.
Identify the upper border of liver dullness in the mid-clavicular line by lightly percussing from lung resonance down toward liver.
An alternate method of estimating liver size is the scratch test.
Keep the diaphragm of your stethoscope over the liver dullness.
Start scratching the abdominal wall starting from the right lower quadrant parallel to the liver edge.
There will be a sudden transition of increased transmission of sound once the liver edge is reached.