The vernier constant is a term used in the context of a vernier scale, which is a visual aid used to take an accurate measurement reading between two graduation markings on a linear scale by using mechanical interpolation. The vernier constant is defined as the ratio of the smallest division of the main scale to the number of divisions on the vernier scale. It is also known as the least count of the vernier caliper. The vernier constant is used to calculate the least count of the vernier caliper by multiplying it with the count of one division of the main scale. The quantity that represents the difference between the size of the smallest division on the main scale and the size of one Vernier division is called the Vernier Constant. The standard for a caliper is usually a constant of 0.02, but it can vary depending on the instrument.