To find a common denominator for the fraction \(\frac{3}{8}\), we typically look for a denominator that can work with other fractions. However, since you only provided one fraction, we can just state that the denominator of \(\frac{3}{8}\) is 8.
If you have another fraction you'd like to combine with \(\frac{3}{8}\), please provide it, and I can help you find the common denominator for both fractions. If you're looking for a common denominator with a set of fractions, the least common multiple (LCM) of the denominators must be found.