Posted On Wed, Jul 19, 2023


A Vernier Caliper is a precision measuring instrument that allows for accurate measurements across various applications. Whether you’re a DIY enthusiast, a machinist, or an engineer, understanding how to read a Vernier Caliper is essential. In this article, we will guide you through the process of reading a Vernier Caliper and explore its various measuring applications. We will also touch upon the digital Vernier Caliper as a modern alternative to the traditional version. So, let’s dive in!

vernier caliper - blog

Understanding the Vernier Caliper:

A Vernier Caliper is a versatile tool that provides precise measurements. It consists of two main scales: the main scale and the vernier scale. The main scale is engraved on the fixed jaw, while the vernier scale is located on the sliding jaw. The vernier scale allows for measurements with higher accuracy than what the main scale alone can provide.

To read a Vernier Caliper accurately, follow these steps:

Step 1: Familiarise Yourself with the Vernier Caliper
• Take a moment to examine the different parts of the Vernier Caliper. This includes the main scale (8), the vernier scale (10), the slider (4), the main measuring faces including the depth measuring blade (6), and the clamping screw (5).

Familiarise Yourself with the Vernier Caliper

Step 2: Understand the Main Scale
• The main scale (8) is the larger scale engraved on the fixed jaw. Each division on the main scale represents a specific measurement unit, such as millimetres or inches. Identify the measurement units and note the value of the smallest division.

Step 3: Examine the Vernier Scale
• The vernier scale (10) is located on the sliding jaw and is slightly smaller than the main scale. It consists of divisions that are spaced closer together than those on the main scale. Each division on the vernier scale represents a fraction of the smallest division on the main scale.

Step 4: Prepare your Caliper for work
• Before measuring, use a soft cloth to clean the measuring and sliding surfaces. The Caliper can be lubricated with a small amount of oil for smooth sliding.
• Before you begin taking measurements with the Vernier Caliper, ensure that the zero lines of the main and the Vernier Caliper coincide, and no gap can be observed between the jaws in the light.
• The slider may be moved only when the clamping screw has been unlocked. Tighten this screw to lock the measurement, if the object needs to be removed before taking the reading.
• Apply suitable force and tighten both fine adjustment screws to get an accurate measurement.

Step 5: Reading the scales
• Your reading will comprise of the sum of the main scale and the vernier scale reading:
• Use the main scale to get the reading, X
• Take the vernier scale reading at the graduation which coincides with the one on the main scale, Y
• Your reading will be the sum of X and Y (X+Y)

Vernier caliper scale

Various Measuring Applications of Vernier Calipers:

Now that you know how to read a Vernier Caliper, let’s explore its various measuring applications:

Vernier Calipers are commonly used to measure the length of objects. Simply place the object between the jaws of the caliper and follow the steps outlined above to obtain an accurate length measurement.

1. Inside Measurement:
For measuring the inner diameter of objects like pipes or holes, open the jaws of the Vernier Caliper and gently insert them into the opening. Close the jaws until they snugly fit against the inner walls, and then read the measurement as described earlier.

Internal measurement

2. Outside Measurement:
To measure the outer diameter of cylindrical objects, such as rods or tubes, position the object between the jaws and close them until they make contact with the outer surface. Read the measurement using the same method as before.

Outside measurement

3. Depth Measurement:
Vernier calipers are equipped with a depth rod that allows for measuring the depth of holes, slots, or recesses. Extend the depth rod and gently place it inside the hole or slot until it touches the bottom. Read the measurement as usual.

4. Step Measurement:
In applications where it is necessary to measure the difference in elevation between two surfaces, Vernier Calipers can be used to measure step height. Position the jaws on each surface and read the measurement accordingly.

Step measurement

Digital Vernier Caliper: A Modern Alternative:

In addition to the traditional Vernier Caliper, there is also a digital version available in the market. A digital Vernier Caliper provides the same accuracy and precision as its traditional counterpart but with the added convenience of digital readings. Instead of reading the scales manually, the Digital Caliper displays the measurement on a digital screen. This makes it easier to read and eliminates the need for interpreting vernier scales. Digital Vernier Calipers often come with additional features such as relative measurement, metric and imperial unit conversions, and zero setting options.

Digital caliper - blog

Digital Vernier Calipers can be a valuable tool for those who prefer a more user-friendly approach to measurement. They are especially useful in scenarios where quick and accurate measurements are required.


By following the steps outlined in this article, you can confidently read a Vernier Caliper and utilize it in various measuring applications. The precision and versatility of Vernier Calipers make them indispensable tools in fields such as engineering, machining, and DIY projects.

To watch video demonstrations on using Vernier Calipers, you can check the following links:

• Vernier Caliper:
• Digital Vernier Caliper:

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