How to Use Digital Calipers

Written By: Spencer Day

Comments: 0

Difficulty

Easy

Steps

Time Required

5 minutes

Introduction

Follow this guide to learn how to use digital calipers to take measurements.

Screw and part dimensions are vital for organizing your electronics repairs, ensuring each screw is put back in its correct place during reassembly—saving you time and frustration!

Calipers precisely measure lengths, thicknesses, and diameters using two sets of jaws. The small inside jaws measure internal diameters, while the large outside jaws measure external diameters, lengths, and widths. A probe on the opposite end measures depth. Digital calipers have the ability to zero and often support more than one unit of measurement.

Dead battery? Follow this guide.

Tools

Step 1

Most digital calipers have the same parts, controls, and buttons:
An on/off button
A zero button that sets the current reading to zero
A units button that switches between imperial and metric measurements, commonly written as mm/inch
A thumb screw that opens and closes the jaws
A locking screw that holds the jaws in place to keep the current measurement
Click here for a more in‑depth look at the different parts of digital calipers.

Step 2

Before using your calipers, clean the inside of the jaws with a fresh cloth or rag to make sure there's no dirt or grime that could affect measurements.

Step 3

To open or close the jaws, press down on the thumb screw and gently roll it in the direction you want the jaw to move.
You don't need to apply much pressure to the thumb screw when opening or closing the jaws.
Pushing too hard can lead to imprecise measurements or inaccurate zeroing.

Step 4

The process of setting zero ensures the measurements you’re about to make are accurate.
Gently close the jaws.
Press the zero button to set the current measurement to zero.
Digital calipers can be zeroed at any point along the scale, not just when the jaws are closed. This can be useful to check the size difference between two components. Take the first measurement, press the zero button, and then take the second measurement. The result is the difference between the two measurements.

Step 5

Open and close the jaws, making sure the calipers measure zero each time the jaws reach their fully closed position. If the reading isn’t exactly 0.00, repeat the previous step.

Step 6

Use the larger external jaws to get external measurements, such as screw lengths or screw head diameters.
Open the jaws wide enough for the object being measured to comfortably fit between them.
Gradually close the jaws until both sides touch the object. Don’t push too hard, yet firm enough to make sure both jaws sit flat against the object.
Check that your object isn’t crooked when you take your measurement.
Read the measurement.
Take the measurement a few times and make sure it's the same—or very close—each time. If you get inconsistent readings, zero the calipers and try again.
Zero the calipers before making another measurement.

Step 7

Use the smaller internal jaws to get internal measurements, such as inside diameters or gaps between parts.
Close the jaws until you can comfortably fit them inside the part.
Gradually open the jaws until both sides touch the object. Don’t pull too hard, yet firm enough to make sure both jaws sit flat against the object’s inside edges.
Read the measurement.
Take the measurement a few times and make sure it's the same—or very close—each time. If you get inconsistent readings, zero the calipers and try again.
Zero the calipers before making another measurement.

Step 8

The locking screw is used to keep the jaws in place after taking a measurement. This is helpful when you don't want your reading to change, or when checking for measurement consistency between multiples of the same part.
Gently remove the item from the jaws, being careful not to bump or shift the jaws.
Twist the locking screw clockwise to tighten it and lock the jaws in place.

Step 9

When you're done using your digital calipers, clean the jaws with a cloth or rag, press the on/off button to turn the calipers off, and store it in its original case in a safe location.
Avoid storing heavy objects on top of your calipers, even when in their case. Calipers can lose accuracy if bent or dropped, and are extra sensitive to dust and grime.