### 8.2. Vertical dimensions

The specification states that top and bottom margins must be at least 1″. The reference point for a LaTeX page is 1″ right of the left edge of the paper and 1″ below the top edge, so the logical margin of zero we specify here gives a physical margin of 1″.

In LaTeX, one does not directly specify the bottom margin; one instead specifies the paperwidth and several vertical dimensions, and the bottom margin is whatever vertical space is left over. First let's consider the height of the header and footer parts of the page.

The specification says nothing about running headers or footers, except for page numbering.

• Preliminary pages display the page number centered at the bottom of the page in lowercase Roman numerals, except for certain pages that display no page number.

• The page number on body and back matter pages must be Arabic. It may appear either in the header or the footer, and may be centered or located at the outside (unbound) edge.

For consistency, this style will default to bottom centered page numbers. The author can always override it with explicit commands at the beginning of the body. This means we can eliminate the header altogether, freeing up more space for page content.

• `\topmargin` specifies the top margin from a point that is already 1″ from the top edge of the paper, so we'll set that to zero.

• `\headheight` is the height of the header, and `\headsep` the vertical distance between the header and page body. We'll set those to zero as well.

• `\textheight` is the height of the text body proper.

• `\footskip` is the vertical distance from the bottom of the body to the bottom of the footer. Assuming that the specification's general rule about double-spaced text holds here, this should be 24 points, or two lines of 12-point type.

The total available height of the page is 11″ minus two 1″ margins or 9″. At 72.27 points per inch, that's 650.43 points. Subtracting the 24 points for the footer gives us a body size of just over 626 points. However, to make sure that the margins are sufficiently wide, we will reduce that by a small value.

nmtthesis2015.sty
```\setlength{\paperheight}{10.9in}
\setlength{\topmargin}{0in}
To insure that the ascenders on the first line of body type don't get too close to the top edge, we specify a 24-point `\topskip` value; this dimension does not reduce the height of the body.
```\setlength{\topskip}{24pt}