Which is the formula for a diminished 7th chord?

A diminished 7th chord is built by stacking minor thirds. The formula for a diminished 7th chord is: root, minor third, diminished fifth, and diminished seventh. In terms of scale degrees, if the root is represented as 1, the chord consists of 1, ♭3, ♭5, and ♭7. For example, in C diminished 7th, the notes are C, E♭, F♯, and A.