To calculate \( \frac{1}{2} \div \frac{1}{4} \), you can multiply by the reciprocal of the second fraction:
\[ \frac{1}{2} \div \frac{1}{4} = \frac{1}{2} \times \frac{4}{1} \]
Now, perform the multiplication:
\[ \frac{1 \times 4}{2 \times 1} = \frac{4}{2} \]
Now, simplify \( \frac{4}{2} \):
\[ \frac{4}{2} = 2 \]
Thus, the result of \( \frac{1}{2} \div \frac{1}{4} \) is
\[ \boxed{2} \]