By the upper part, do you mean the section that went into the sky?
Let's use
this as a reference, since it's the largest depiction of the skyward pillar IIRC. The sky portion of the pillar is 1481 pixels, while the width of the pillar is 1011 px. On the other hand, the depth of the pillar is
more than twice the width, so that only increases the calc by like 64% (unless, of course, you can find a larger depiction of the pillar).
However, Meliodas did it on the surface of Danafor, meaning the part that went into the sky didn't encounter any resistance. So I'm not sure if we can actually consider it to be applicable.