Index: src/viewport.cpp
===================================================================
--- src/viewport.cpp	(revision 19751)
+++ src/viewport.cpp	(working copy)
@@ -150,6 +150,10 @@
 static TileInfo *_cur_ti;
 bool _draw_bounding_boxes = false;
 
+/** Height change in meters of one Z unit difference, as displayed at the mini map. */
+static const int _minimap_height_step = 25;
+
+
 static Point MapXYZToViewport(const ViewPort *vp, int x, int y, int z)
 {
 	Point p = RemapCoords(x, y, z);
@@ -2169,8 +2173,8 @@
 	return false;
 }
 
-/** Calculates height difference between one tile and another
- * Multiplies the result to suit the standard given by minimap - 50 meters high
+/** Calculates height difference between one tile and another.
+ * Multiplies the result to suit the standard given by the minimap.
  * To correctly get the height difference we need the direction we are dragging
  * in, as well as with what kind of tool we are dragging. For example a horizontal
  * autorail tool that starts in bottom and ends at the top of a tile will need the
@@ -2251,8 +2255,8 @@
 	}
 
 	if (swap) Swap(h0, h1);
-	/* Minimap shows height in intervals of 50 meters, let's do the same */
-	return (int)(h1 - h0) * 50;
+	/* Minimap shows height in intervals of _minimap_height_step meters for each step, let's do the same. */
+	return (int)(h1 - h0) * _minimap_height_step;
 }
 
 static const StringID measure_strings_length[] = {STR_NULL, STR_MEASURE_LENGTH, STR_MEASURE_LENGTH_HEIGHTDIFF};