The Percentage Elongation calculator computes the ratio of change in length to original length.

INSTRUCTIONS: Choose units and enter the following:

• (L₀)  This is the initial length.
• (ΔL)  This is the change in length.

Percent Elongation (PE):  The calculator return the ratio of elongation as a percent.

The Math / Science

The formula for percent elongation is:

%elong = ΔL / L₀

where:

• ΔL is the change in length
• L₀ is the initial length

Percent Elongation used in the computation of engineering stress and strain.¹

See also

Strain (Engineering, Basic Definition)

1. ^ Fundamentals of Engineering. 8th edition, 2nd Revision.  National Council of Examiners for Engineering and Surveying (NCEES) - 2001. ISBN 978-1-932613-59-9.  pg 33