How to Read a Vernier Caliper Measurement

Measure the distance you wish to figure out using the vernier caliper. Use the proper set of jaws -- the small jaws are used for measuring the inside diameter of an object, while the larger jaws are used to measure an object that fits between them -- to ensure the most accurate reading.

Find out how exact your caliper is. This information is generally written somewhere on the moving scale. Common calipers read to .05 millimeters and .001 inches, although other types of calipers exist. This tells you what units the small ticks on the movable caliper read, and therefore, how exact a measurement you can get.

Read the large number -- ignore the small notches at first -- on the fixed scale to the left of the zero reading on the movable scale. This is the length of the object in centimeters, or tenths of an inch if your caliper displays the English system.

Read the small notch, often accompanied by a small number, on the fixed scale immediately to the left of the zero reading on the movable scale. This is the length of the object in millimeters.

Find where one of the tick marks on the movable scale lines up most exactly with one of the tick marks on the fixed scale. Read the measurement on the fixed scale where these ticks line up.

Add all of your measurements up. Start with your largest measurement and work your way to the smallest measurement, the one you found from reading the movable scale.