What types of caliper gages are available and what are their differences? The broad categories of types of caliper gages include, digital caliper gage, dial caliper gage, external caliper gage, internal caliper gage, metric caliper gage, and inch caliper gage. Digital and dial calipers differ in build and output style. Some metrologists prefer to have more manual control over a measurement, and therefore may prefer a dial caliper gage that allows them to determine the output. Others might like the consistency offered by an electronic tool design and the digital output option. Internal and external caliper gages differ in what they are intended to measure. Internal caliper gages take inside measurements of an object, while external caliper gages take outside measurements. These calipers require gentle handling so as to avoid bending or damage during adjustment and positioning. Metric and inch caliper gages simply differ in the unit of measurement output. Most often, caliper gages are built as overlapping types rather than each one of these types being built independently. Caliper gages are commonly able to switch between metric and inch output and likely can manage both manual and digital measurements. Something to keep in mind when buying a caliper gage is that if you do not see a specific design feature that you have in mind, just ask. These tools come in a huge variety and there may be a way in which to create the specific caliper gage you are hoping for or to adjust another version to match the needs you have in mind.