# why is k=10 is commonly used in cross validation? [duplicate]

many blogs say that k=10 is the most commonly number of folds in cross validation. But what is the mathematical explanation behind?

• Possible duplicate of Choice of K in K-fold cross-validation. In short, there are some advantages to having around $k=10$ folds, but the exact number of $10$ has no special benefit over, say $9$ or $11$. – Frans Rodenburg Jul 21 '19 at 3:57