I play at 1440p on a 25" monitor. I used the blue marble program to increase the text size. You can also manually edit the font sizes. The fonts are located at the location
\Steam\steamapps\common\Sid Meier's Civilization IV Beyond the Sword\Beyond the Sword\Resource\Themes\Civ4\Civ4Theme_Common.thm
The font setting is around line 370, you can bump those up 1-2 sizes. Much better now. These are my settings:
with .Font
{
// Anti-aliased font requires the Text combine
// to be BlendSource instead of Source, which means
// there must be an ALPHA channel in all fonts
// To save memory (both system and video) unused fonts are currently commented out.
// Civ really only uses the following font sizes and styles:
// 1 - normal
// 2 - normal, 2 - bold, 2 - italic
// 3 - normal, 3 - bold
// 4 - normal, 4 - bold
// -Moose
with SF_CtrlTheme_Civ4_Control_Font
{
// GFont .Size0_Normal = GFont("Sylfaen", "Regular", 13, GFlags(GFontFeature, GFC_FONT_ALPHA));
// GFont .Size0_Bold = GFont("Sylfaen", "Bold", 13, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ALPHA));
// GFont .Size0_Italic = GFont("Sylfaen", "Italic", 13, GFlags(GFontFeature, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
// GFont .Size0_BoldItalic = GFont("Sylfaen", "Bold Italic", 13, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
GFont .Size1_Normal = GFont("Sylfaen", "Regular", 15, GFlags(GFontFeature, GFC_FONT_ALPHA));
// GFont .Size1_Bold = GFont("Sylfaen", "Bold", 15, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ALPHA));
// GFont .Size1_Italic = GFont("Sylfaen", "Italic", 15, GFlags(GFontFeature, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
// GFont .Size1_BoldItalic = GFont("Sylfaen", "Bold Italic", 15, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
GFont .Size2_Normal = GFont("Sylfaen", "Regular", 17, GFlags(GFontFeature, GFC_FONT_ALPHA));
GFont .Size2_Bold = GFont("Sylfaen", "Bold", 17, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ALPHA));
GFont .Size2_Italic = GFont("Sylfaen", "Italic", 17, GFlags(GFontFeature, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
// GFont .Size2_BoldItalic = GFont("Sylfaen", "Bold Italic", 17, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
GFont .Size3_Normal = GFont("Sylfaen", "Regular", 17, GFlags(GFontFeature, GFC_FONT_ALPHA));
GFont .Size3_Bold = GFont("Sylfaen", "Bold", 17, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ALPHA));
// GFont .Size3_Italic = GFont("Sylfaen", "Italic", 17, GFlags(GFontFeature, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
// GFont .Size3_BoldItalic = GFont("Sylfaen", "Bold Italic", 17, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
GFont .Size4_Normal = GFont("Sylfaen", "Regular", 22, GFlags(GFontFeature, GFC_FONT_ALPHA));
GFont .Size4_Bold = GFont("Sylfaen", "Bold", 22, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ALPHA));
// GFont .Size4_Italic = GFont("Sylfaen", "Italic", 22, GFlags(GFontFeature, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
// GFont .Size4_BoldItalic = GFont("Sylfaen", "Bold Italic", 22, GFlags(GFontFeature, GFC_FONT_BOLD, GFC_FONT_ITALIC, GFC_FONT_ALPHA), 0, GRectMargin(1));
}