# Percent Elongation

## Definition - What does Percent Elongation mean?

Percent elongation is a measurement that captures the amount a material will plastically and elastically deform up to fracture. Percent elongation is one way to measure and quantify the ductility of a material. The material's final length is compared with its original length to determine the percent elongation and the material’s ductility.

Percent elongation may also be known as percentage elongation.

## Corrosionpedia explains Percent Elongation

Percent elongation is typically carried out during a material tensile test. Rather than measuring the entire length of the specimen before and after the tensile test, a gauge records the elongation over a set volume of material in the center of the test specimen. The fracture will occur in between the ends of the gauge. The distance between the two ends is recorded in real-time in conjunction with the force being applied by the tensile machine so that the percent elongation can be mapped out over time with the force being applied.

To calculate percent elongation, the original length of the gauge span is subtracted from the final length. Then the solution from that subtraction is divided by the original length and multiplied by 100 to obtain the percent elongation. The equation is:

Percent Elongation = 100 x ((Final Length - Original Length) x Original Length)

Percent elongation is incredibly useful to determine the ductility of a material. A material with a higher percentage is a more ductile material, while a material with a lower percentage will be more brittle. Although there are exceptions, percent elongation measurements can also be used to give a general sense of what the malleability and toughness properties may be.