Initial Length
| Initial Length Formulas | ||
| \( l_i = l_f \;/\; \overrightarrow{\alpha_l} \; \left( T_f - T_i \right) + 1 \) (Linear Thermal Expansion Coefficient) \( l_i = \Delta l \;/\; \epsilon \) (Strain) | ||
| Symbol | English | Metric | 
| \( l_i \) = Initial Length | \(ft\) | \(m\) | 
| \( l_f \) = Final Length | \(ft\) | \(m\) | 
| \( \Delta l \) = Length Differential | \(ft\) | \(m\) | 
| \( \overrightarrow{\alpha_l} \) (Greek symbol alpha) = Linear Thermal Expansion Coefficient | \(1\;/\;F\) | \(1\;/\;C\) | 
| \( \epsilon \) (Greek symbol epsilon) = Strain | \(in\;/\;in\) | \(mm\;/\;mm\) | 
| \( T_f \) = Final Temperature | \(F\) | \(C\) | 
| \( T_i \) = Initial Temperature | \(F\) | \(C\) | 

