Digital calipers are available with both an inch and metric scale. In the event one is encountered in metric only, a simple mathematical conversion is necessary to convert it to inches. Digital calipers are more accurate than dial calipers because no interpolation is necessary for the last hundred thousandths. Dial calipers use a needle so when the needle falls between increment marks, judge the distance between the increments to arrive at an approximate number. Digital calipers on the other hand, display the entire number with no guess work.
Close the jaws of the caliper completely and press the 0 button under the digital screen.
Read the slider scale by looking for the last whole number that can be seen at the marker line to the right of the lower jaw. This is in whole inches, unless the object being measured is less than an inch. If this is the case, your measurement will be in the digital display only showing the part of an inch.
Read the digital display as hundreds and thousandths of an inch. For example: 5.765 breaks down to 5 inches and .765 hundreds of an inch. The 76 is hundreds and the 5 represents thousandths of an inch.
Read a metric scale the same way. A 6-inch scale calipers is 150 millimeters graduated in increments of 5 or 6 inches. Read the whole metric number on the sliding scale plus the numbers in the digital screen equal the metric size to the fraction of a centimeter. For example: 40.865 or 40 millimeters and .865 hundreds of a millimeter.
Convert the metric number to inches, by dividing 40.865 millimeters by 25.4 to get 1.6088582 inches.
