Stretch describes how far a fabric gives and how well it returns. Elastane increases both, but the construction of the fabric matters at least as much.
A pattern is drafted for a defined amount of stretch. Using a fabric with noticeably more or less stretch than intended changes the fit even though the pattern is unchanged.

Digitize sewing patterns without tracing.
Test PatternScan Pro free for 14 days with the full feature set. You need your smartphone, a printer and one pattern you always wanted digital.