diff --git a/util/hb-ot-shape-closure.cc b/util/hb-ot-shape-closure.cc
index 03de7e6..859f9a6 100644
--- a/util/hb-ot-shape-closure.cc
+++ b/util/hb-ot-shape-closure.cc
@@ -110,6 +110,6 @@
 int
 main (int argc, char **argv)
 {
-  main_font_text_t<shape_closure_consumer_t> driver;
+  main_font_text_t<shape_closure_consumer_t, FONT_SIZE_NONE, 0> driver;
   return driver.main (argc, argv);
 }
diff --git a/util/hb-shape.cc b/util/hb-shape.cc
index 01081ea..f38f387 100644
--- a/util/hb-shape.cc
+++ b/util/hb-shape.cc
@@ -126,6 +126,6 @@
 int
 main (int argc, char **argv)
 {
-  main_font_text_t<shape_consumer_t<output_buffer_t> > driver;
+  main_font_text_t<shape_consumer_t<output_buffer_t>, FONT_SIZE_UPEM, 0> driver;
   return driver.main (argc, argv);
 }
diff --git a/util/hb-view.cc b/util/hb-view.cc
index 26fad66..ef75e6d 100644
--- a/util/hb-view.cc
+++ b/util/hb-view.cc
@@ -29,9 +29,12 @@
 #include "shape-consumer.hh"
 #include "view-cairo.hh"
 
+#define DEFAULT_FONT_SIZE 256
+#define SUBPIXEL_BITS 8
+
 int
 main (int argc, char **argv)
 {
-  main_font_text_t<shape_consumer_t<view_cairo_t> > driver;
+  main_font_text_t<shape_consumer_t<view_cairo_t>, DEFAULT_FONT_SIZE, SUBPIXEL_BITS> driver;
   return driver.main (argc, argv);
 }
diff --git a/util/helper-cairo.cc b/util/helper-cairo.cc
index ee940ae..d576c3f 100644
--- a/util/helper-cairo.cc
+++ b/util/helper-cairo.cc
@@ -70,8 +70,7 @@
 }
 
 cairo_scaled_font_t *
-helper_cairo_create_scaled_font (const font_options_t *font_opts,
-				 double font_size)
+helper_cairo_create_scaled_font (const font_options_t *font_opts)
 {
   hb_font_t *font = hb_font_reference (font_opts->get_font ());
 
@@ -105,7 +104,8 @@
 
   cairo_matrix_init_identity (&ctm);
   cairo_matrix_init_scale (&font_matrix,
-			   font_size, font_size);
+			   font_opts->font_size_x,
+			   font_opts->font_size_y);
   font_options = cairo_font_options_create ();
   cairo_font_options_set_hint_style (font_options, CAIRO_HINT_STYLE_NONE);
   cairo_font_options_set_hint_metrics (font_options, CAIRO_HINT_METRICS_OFF);
@@ -423,7 +423,7 @@
 			       hb_buffer_t         *buffer,
 			       const char          *text,
 			       unsigned int         text_len,
-			       double               scale,
+			       int                  scale_bits,
 			       hb_bool_t            utf8_clusters)
 {
   memset (l, 0, sizeof (*l));
@@ -456,16 +456,16 @@
   for (i = 0; i < (int) l->num_glyphs; i++)
   {
     l->glyphs[i].index = hb_glyph[i].codepoint;
-    l->glyphs[i].x = ( hb_position->x_offset + x) * scale;
-    l->glyphs[i].y = (-hb_position->y_offset + y) * scale;
+    l->glyphs[i].x = scalbn ( hb_position->x_offset + x, scale_bits);
+    l->glyphs[i].y = scalbn (-hb_position->y_offset + y, scale_bits);
     x +=  hb_position->x_advance;
     y += -hb_position->y_advance;
 
     hb_position++;
   }
   l->glyphs[i].index = -1;
-  l->glyphs[i].x = x * scale;
-  l->glyphs[i].y = y * scale;
+  l->glyphs[i].x = scalbn (x, scale_bits);
+  l->glyphs[i].y = scalbn (y, scale_bits);
 
   if (l->num_clusters) {
     memset ((void *) l->clusters, 0, l->num_clusters * sizeof (l->clusters[0]));
diff --git a/util/helper-cairo.hh b/util/helper-cairo.hh
index 567777e..ed55a45 100644
--- a/util/helper-cairo.hh
+++ b/util/helper-cairo.hh
@@ -33,8 +33,7 @@
 
 
 cairo_scaled_font_t *
-helper_cairo_create_scaled_font (const font_options_t *font_opts,
-				 double font_size);
+helper_cairo_create_scaled_font (const font_options_t *font_opts);
 
 extern const char *helper_cairo_supported_formats[];
 
@@ -76,7 +75,7 @@
 			       hb_buffer_t         *buffer,
 			       const char          *text,
 			       unsigned int         text_len,
-			       double               scale,
+			       int                  scale_bits,
 			       hb_bool_t            utf8_clusters);
 
 #endif
diff --git a/util/main-font-text.hh b/util/main-font-text.hh
index ac51b2d..628cdf9 100644
--- a/util/main-font-text.hh
+++ b/util/main-font-text.hh
@@ -31,12 +31,12 @@
 
 /* main() body for utilities taking font and processing text.*/
 
-template <typename consumer_t>
+template <typename consumer_t, int default_font_size, int subpixel_bits>
 struct main_font_text_t
 {
   main_font_text_t (void)
 		  : options ("[FONT-FILE] [TEXT]"),
-		    font_opts (&options),
+		    font_opts (&options, default_font_size, subpixel_bits),
 		    input (&options),
 		    consumer (&options) {}
 
diff --git a/util/options.cc b/util/options.cc
index 44b11c8..7387a56 100644
--- a/util/options.cc
+++ b/util/options.cc
@@ -265,7 +265,6 @@
     {"foreground",	0, 0, G_OPTION_ARG_STRING,	&this->fore,			"Set foreground color (default: " DEFAULT_FORE ")",	"rrggbb/rrggbbaa"},
     {"line-space",	0, 0, G_OPTION_ARG_DOUBLE,	&this->line_space,		"Set space between lines (default: 0)",			"units"},
     {"margin",		0, 0, G_OPTION_ARG_CALLBACK,	(gpointer) &parse_margin,	"Margin around output (default: " G_STRINGIFY(DEFAULT_MARGIN) ")","one to four numbers"},
-    {"font-size",	0, 0, G_OPTION_ARG_DOUBLE,	&this->font_size,		"Font size (default: " G_STRINGIFY(DEFAULT_FONT_SIZE) ")","size"},
     {NULL}
   };
   parser->add_group (entries,
@@ -350,6 +349,28 @@
 		     this);
 }
 
+static gboolean
+parse_font_size (const char *name G_GNUC_UNUSED,
+		 const char *arg,
+		 gpointer    data,
+		 GError    **error G_GNUC_UNUSED)
+{
+  font_options_t *font_opts = (font_options_t *) data;
+  if (0 == strcmp (arg, "upem"))
+  {
+    font_opts->font_size_y = font_opts->font_size_x = FONT_SIZE_UPEM;
+    return true;
+  }
+  switch (sscanf (arg, "%lf %lf", &font_opts->font_size_x, &font_opts->font_size_y)) {
+    case 1: font_opts->font_size_y = font_opts->font_size_x;
+    case 2: return true;
+    default:
+      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
+		   "%s argument should be one to four space-separated numbers",
+		   name);
+      return false;
+  }
+}
 void
 font_options_t::add_options (option_parser_t *parser)
 {
@@ -370,10 +391,21 @@
     parser->free_later (text);
   }
 
+  char *font_size_text;
+  if (default_font_size == FONT_SIZE_UPEM)
+    font_size_text = (char *) "Font size (default: upem)";
+  else
+  {
+    font_size_text = g_strdup_printf ("Font size (default: %d)", default_font_size);
+    parser->free_later (font_size_text);
+  }
+
   GOptionEntry entries[] =
   {
     {"font-file",	0, 0, G_OPTION_ARG_STRING,	&this->font_file,		"Set font file-name",			"filename"},
     {"face-index",	0, 0, G_OPTION_ARG_INT,		&this->face_index,		"Set face index (default: 0)",		"index"},
+    {"font-size",	0, default_font_size ? 0 : G_OPTION_FLAG_HIDDEN,
+			      G_OPTION_ARG_CALLBACK,	(gpointer) &parse_font_size,	font_size_text,				"1/2 numbers or 'upem'"},
     {"font-funcs",	0, 0, G_OPTION_ARG_STRING,	&this->font_funcs,		text,					"impl"},
     {NULL}
   };
@@ -515,8 +547,14 @@
 
   font = hb_font_create (face);
 
-  unsigned int upem = hb_face_get_upem (face);
-  hb_font_set_scale (font, upem, upem);
+  if (font_size_x == FONT_SIZE_UPEM)
+    font_size_x = hb_face_get_upem (face);
+  if (font_size_y == FONT_SIZE_UPEM)
+    font_size_y = hb_face_get_upem (face);
+
+  int scale_x = (int) scalbnf (font_size_x, subpixel_bits);
+  int scale_y = (int) scalbnf (font_size_y, subpixel_bits);
+  hb_font_set_scale (font, scale_x, scale_y);
   hb_face_destroy (face);
 
   void (*set_font_funcs) (hb_font_t *) = NULL;
diff --git a/util/options.hh b/util/options.hh
index 223778d..8b9b10e 100644
--- a/util/options.hh
+++ b/util/options.hh
@@ -143,7 +143,8 @@
 #define DEFAULT_MARGIN 16
 #define DEFAULT_FORE "#000000"
 #define DEFAULT_BACK "#FFFFFF"
-#define DEFAULT_FONT_SIZE 256
+#define FONT_SIZE_UPEM 0x7FFFFFFF
+#define FONT_SIZE_NONE 0
 
 struct view_options_t : option_group_t
 {
@@ -153,7 +154,6 @@
     back = DEFAULT_BACK;
     line_space = 0;
     margin.t = margin.r = margin.b = margin.l = DEFAULT_MARGIN;
-    font_size = DEFAULT_FONT_SIZE;
 
     add_options (parser);
   }
@@ -167,7 +167,6 @@
   struct margin_t {
     double t, r, b, l;
   } margin;
-  double font_size;
 };
 
 
@@ -273,9 +272,14 @@
 
 struct font_options_t : option_group_t
 {
-  font_options_t (option_parser_t *parser) {
+  font_options_t (option_parser_t *parser,
+		  int default_font_size_,
+		  unsigned int subpixel_bits_) {
+    default_font_size = default_font_size_;
+    subpixel_bits = subpixel_bits_;
     font_file = NULL;
     face_index = 0;
+    font_size_x = font_size_y = default_font_size;
     font_funcs = NULL;
 
     font = NULL;
@@ -292,6 +296,10 @@
 
   const char *font_file;
   int face_index;
+  int default_font_size;
+  unsigned int subpixel_bits;
+  mutable double font_size_x;
+  mutable double font_size_y;
   const char *font_funcs;
 
   private:
diff --git a/util/view-cairo.cc b/util/view-cairo.cc
index 666013e..160250e 100644
--- a/util/view-cairo.cc
+++ b/util/view-cairo.cc
@@ -54,7 +54,7 @@
 void
 view_cairo_t::render (const font_options_t *font_opts)
 {
-  cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts, view_options.font_size);
+  cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts);
   double w, h;
   get_surface_size (scaled_font, &w, &h);
   cairo_t *cr = helper_cairo_create_context (w, h, &view_options, &output_options);
diff --git a/util/view-cairo.hh b/util/view-cairo.hh
index 9dea06e..cb52373 100644
--- a/util/view-cairo.hh
+++ b/util/view-cairo.hh
@@ -37,7 +37,7 @@
 	       : output_options (parser, helper_cairo_supported_formats),
 		 view_options (parser),
 		 direction (HB_DIRECTION_INVALID),
-		 lines (0), scale (1.0) {}
+		 lines (0), scale_bits (0) {}
   ~view_cairo_t (void) {
     if (debug)
       cairo_debug_reset_static_data ();
@@ -46,7 +46,7 @@
   void init (const font_options_t *font_opts)
   {
     lines = g_array_new (false, false, sizeof (helper_cairo_line_t));
-    scale = double (view_options.font_size) / hb_face_get_upem (hb_font_get_face (font_opts->get_font ()));
+    scale_bits = -font_opts->subpixel_bits;
   }
   void new_line (void)
   {
@@ -71,7 +71,7 @@
   {
     direction = hb_buffer_get_direction (buffer);
     helper_cairo_line_t l;
-    helper_cairo_line_from_buffer (&l, buffer, text, text_len, scale, utf8_clusters);
+    helper_cairo_line_from_buffer (&l, buffer, text, text_len, scale_bits, utf8_clusters);
     g_array_append_val (lines, l);
   }
   void finish (const font_options_t *font_opts)
@@ -100,7 +100,7 @@
 
   hb_direction_t direction; // Remove this, make segment_properties accessible
   GArray *lines;
-  double scale;
+  int scale_bits;
 };
 
 #endif