To calculate \(-50 \div -150\), we can start by dividing the absolute values:
\[ \frac{50}{150} = \frac{1}{3} \]
Since both numbers being divided are negative, the result will be positive:
\[ -50 \div -150 = \frac{1}{3} \]
So, the final answer is:
\[ \frac{1}{3} \]