diff --git a/src/build_vehicle_gui.cpp b/src/build_vehicle_gui.cpp
--- a/src/build_vehicle_gui.cpp
+++ b/src/build_vehicle_gui.cpp
@@ -890,7 +890,7 @@ void DrawEngineList(VehicleType type, in
 	int count_width = 0;
 	if (show_count) {
 		replace_icon = GetSpriteSize(SPR_GROUP_REPLACE_ACTIVE);
-		SetDParamMaxDigits(0, 3);
+		SetDParamMaxDigits(0, 3, FS_SMALL);
 		count_width = GetStringBoundingBox(STR_TINY_BLACK_COMA).width;
 	}
 
diff --git a/src/depot_gui.cpp b/src/depot_gui.cpp
--- a/src/depot_gui.cpp
+++ b/src/depot_gui.cpp
@@ -601,7 +601,7 @@ struct DepotWindow : Window {
 				uint min_height = 0;
 
 				if (this->type == VEH_TRAIN) {
-					SetDParamMaxValue(0, 1000);
+					SetDParamMaxValue(0, 1000, 0, FS_SMALL);
 					SetDParam(1, 1);
 					this->count_width = GetStringBoundingBox(STR_TINY_BLACK_DECIMAL).width + WD_FRAMERECT_LEFT + WD_FRAMERECT_RIGHT;
 				} else {
diff --git a/src/gfx.cpp b/src/gfx.cpp
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -1689,6 +1689,24 @@ byte GetDigitWidth(FontSize size)
 	return width;
 }
 
+/**
+ * Return the digit with the biggest width.
+ * @param size  Font of the digit
+ * @return Broadest digit.
+ */
+uint GetBroadestDigit(FontSize size)
+{
+	uint digit = 0;
+	byte width = 0;
+	for (char c = '0'; c <= '9'; c++) {
+		byte w = GetCharacterWidth(size, c);
+		if (w > width) {
+			width = w;
+			digit = c - '0';
+		}
+	}
+	return digit;
+}
 
 void ScreenSizeChanged()
 {
diff --git a/src/gfx_func.h b/src/gfx_func.h
--- a/src/gfx_func.h
+++ b/src/gfx_func.h
@@ -150,6 +150,7 @@ bool ToggleFullScreen(bool fs);
 /* gfx.cpp */
 byte GetCharacterWidth(FontSize size, uint32 key);
 byte GetDigitWidth(FontSize size = FS_NORMAL);
+uint GetBroadestDigit(FontSize size = FS_NORMAL);
 
 /**
  * Get height of a character for a given font size.
diff --git a/src/graph_gui.cpp b/src/graph_gui.cpp
--- a/src/graph_gui.cpp
+++ b/src/graph_gui.cpp
@@ -504,7 +504,7 @@ public:
 			}
 		} else {
 			/* Draw the label under the data point rather than on the grid line. */
-			SetDParamMaxValue(0, this->x_values_start + this->num_on_x_axis * this->x_values_increment);
+			SetDParamMaxValue(0, this->x_values_start + this->num_on_x_axis * this->x_values_increment, 0, FS_SMALL);
 			x_label_width = GetStringBoundingBox(STR_GRAPH_Y_LABEL_NUMBER).width;
 		}
 
diff --git a/src/group_gui.cpp b/src/group_gui.cpp
--- a/src/group_gui.cpp
+++ b/src/group_gui.cpp
@@ -183,7 +183,7 @@ private:
 		}
 		this->tiny_step_height = max(this->tiny_step_height, this->column_size[VGC_PROFIT].height);
 
-		SetDParamMaxValue(0, GroupStatistics::Get(this->vli.company, ALL_GROUP, this->vli.vtype).num_vehicle, 3);
+		SetDParamMaxValue(0, GroupStatistics::Get(this->vli.company, ALL_GROUP, this->vli.vtype).num_vehicle, 3, FS_SMALL);
 		this->column_size[VGC_NUMBER] = GetStringBoundingBox(STR_TINY_COMMA);
 		this->tiny_step_height = max(this->tiny_step_height, this->column_size[VGC_NUMBER].height);
 
diff --git a/src/strings.cpp b/src/strings.cpp
--- a/src/strings.cpp
+++ b/src/strings.cpp
@@ -96,25 +96,27 @@ void StringParameters::ShiftParameters(u
  * @param max_value The biggest value which shall be displayed.
  *                  For the result only the number of digits of \a max_value matter.
  * @param min_count Minimum number of digits independent of \a max.
+ * @param size  Font of the number
  */
-void SetDParamMaxValue(uint n, uint64 max_value, uint min_count)
+void SetDParamMaxValue(uint n, uint64 max_value, uint min_count, FontSize size)
 {
 	uint num_digits = 1;
 	while (max_value >= 10) {
 		num_digits++;
 		max_value /= 10;
 	}
-	SetDParamMaxDigits(n, max(min_count, num_digits));
+	SetDParamMaxDigits(n, max(min_count, num_digits), size);
 }
 
 /**
  * Set DParam n to some number that is suitable for string size computations.
  * @param n Index of the string parameter.
  * @param count Number of digits which shall be displayable.
+ * @param size  Font of the number
  */
-void SetDParamMaxDigits(uint n, uint count)
+void SetDParamMaxDigits(uint n, uint count, FontSize size)
 {
-	static const uint biggest_digit = 8; ///< Digit with the biggest string width.
+	uint biggest_digit = GetBroadestDigit(size);
 	uint64 val = biggest_digit;
 	for (; count > 1; count--) {
 		val = 10 * val + biggest_digit;
diff --git a/src/strings_func.h b/src/strings_func.h
--- a/src/strings_func.h
+++ b/src/strings_func.h
@@ -155,8 +155,8 @@ static inline void SetDParam(uint n, uin
 	_global_string_params.SetParam(n, v);
 }
 
-void SetDParamMaxValue(uint n, uint64 max_value, uint min_count = 0);
-void SetDParamMaxDigits(uint n, uint count);
+void SetDParamMaxValue(uint n, uint64 max_value, uint min_count = 0, FontSize size = FS_NORMAL);
+void SetDParamMaxDigits(uint n, uint count, FontSize size = FS_NORMAL);
 
 void SetDParamStr(uint n, const char *str);
 
diff --git a/src/timetable_gui.cpp b/src/timetable_gui.cpp
--- a/src/timetable_gui.cpp
+++ b/src/timetable_gui.cpp
@@ -200,7 +200,7 @@ struct TimetableWindow : Window {
 	{
 		switch (widget) {
 			case WID_VT_ARRIVAL_DEPARTURE_PANEL:
-				SetDParamMaxValue(0, MAX_YEAR * DAYS_IN_YEAR);
+				SetDParamMaxValue(0, MAX_YEAR * DAYS_IN_YEAR, 0, FS_SMALL);
 				this->deparr_time_width = GetStringBoundingBox(STR_JUST_DATE_TINY).width;
 				this->deparr_abbr_width = max(GetStringBoundingBox(STR_TIMETABLE_ARRIVAL_ABBREVIATION).width, GetStringBoundingBox(STR_TIMETABLE_DEPARTURE_ABBREVIATION).width);
 				size->width = WD_FRAMERECT_LEFT + this->deparr_abbr_width + 10 + this->deparr_time_width + WD_FRAMERECT_RIGHT;