Close the jaws and check that the reading is at zero
Identify the type of caliper: vernier, dial, or digital
Place the object between the jaws or against the depth rod
Read the main scale value just before the zero mark on the sliding scale
Read the vernier, dial, or digital display value
Add the main scale value and the smaller scale value
For a vernier caliper, find the vernier line that lines up exactly with a main scale line
For a dial caliper, read the dial pointer value and add it to the main scale
For a digital caliper, read the number shown on the screen
Include the correct unit of measurement
Record the final measurement