Stem length charts are just starting points. After that you listen to your body to determine the ideal length.

Too long a stem makes you feel stretched out, pulls you toward the nose of the saddle, and often causes stiff necks on longish rides.

Too short a stem, makes you feel crowded, especially if you try to tuck low when on the drops.

If you don't feel either reason to change, your bars are just right (or close enough to pass) right where they are.

My favorite check for stem length is to ride past a reflective store window, in my normal position. I note the angle my arm makes to the torso. I consider a 90° arm to spine angle about ideal. If I'm "reaching" up or down, the stem is too long or short respectively.

40+ years ago, a coach used this alternate method. Sit up in the saddle, close your eyes, reach out in front of you as you lean forward to find the bars. If you miss and hit your chin on the stem, the bar's in the wrong place.