To evaluate the expression \(2d + 3\) when \(d = 8\), we can substitute \(d\) with \(8\):
\[ 2d + 3 = 2(8) + 3 \]
Next, we calculate \(2 \times 8\):
\[ 2 \times 8 = 16 \]
Now, we add \(3\) to \(16\):
\[ 16 + 3 = 19 \]
Therefore, the value of \(2d + 3\) when \(d = 8\) is
\[ \boxed{19} \]