# Accuracy and Precision: What’s the Difference?

While these terms can be used interchangeably, they are different. In the scientific, manufacturing, and engineering fields, understanding those differences is important to your measurement goals, quality assurance needs, and/or application requirements.

It is important to note that measurement systems can be precise but not accurate and accurate but not precise, neither, or both! To understand these statements for your measurement system let’s break down the definition of each.

## Accuracy

Simply put accuracy is how close a measured value is to its true or original value. Accuracy comes into play greatly with tolerance as components can be manufactured to specified tolerance values – known values. The machine used to manufacture components can be deemed accurate if it completes the component within those tolerances.

Calipers are typically used to verify the accuracy of components’ dimensions or tolerances for quality checks.

## Precision

Precision is how close the measurements are to each other. Repeatability and reproducibility are both related to precision. Repeatability is necessary for manufacturing applications, especially for mass-producing components.

Precision linear shafts are a product that MISUMI carries. The precision is the consistency of the diameter of the shaft along its entire length.

## How They Differ

The difference between the two terms is simple. While there will always be an actual value that they are compared with, it is what value they are measured against that sets them apart. Precision reflects how reproducible the measurements are. Accuracy is how close a measurement is to a known value.

Applications can be both accurate and precise. The precision linear shafts are an example that they must be both accurate and precise, accurate to meet tolerance criteria and precise to be able to reproduce the same shaft in higher quantities.

After reading the definitions of each of these, one can then determine which or if both apply to their measurement systems depending on the end goal. A dartboard player can be both accurate and precise by hitting the bullseye consistently with every shot or a tennis player can be accurate with their shots by making the tennis ball hit their racket’s sweet spot every time.

With that being said, shoot your shot with MISUMI’s top measuring brands to help measure your accurate and precise measurements including Mitutoyo, A&D Weighing, Shinwa Rules, and Niigata Seiki. Explore products including calipers, rulers, balances, and height gauges today!