Calipers are measuring tools that are designed for extremely accurate and precise measurements. They are used for metal working, medicine, woodworking, making guns and other fields in which incredibly accurate measurements are necessary. Calipers are specially designed to measure things using two different tools, the main caliper and the vernier scale, which measures very small fractions of an inch.
Read the number of full inches. These numbers will be the largest numbers on the "main scale" of the caliper and will be spaced 1 inch apart.
Count the number of subdivisions between inches on the main caliper. Often these inches will be divided into 1/16-inch marks.
Read the main caliper. Count the number of hash marks away from the previous "inch" marker. Divide this number by your result from Step 2. For example, if your main caliper is divided into 16ths of an inch, and you count 4 hash marks from the 2-inch marker, then your main caliper measurement is 2 plus 4/16, or 2.25 inches.
Read the vernier scale. Look along the vernier scale until you see a line on it that matches up with any of the lines on the main scale. There will be a number next to this line on the vernier scale. This number corresponds to the number of thousandths of an inch to add. For example, if the line with a 12 on it on the vernier scale lines up with one of the main caliper lines, then that corresponds to 0.012 inches.
Add your numbers. Add the measurement from the main caliper (in this example 2.25 inches) with the measurement from the vernier scale (0.012 inches) to get your final measurement (2.262 inches).
