Index: trunk/src/org/openstreetmap/josm/data/projection/proj/TransverseMercator.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/projection/proj/TransverseMercator.java	(revision 13165)
+++ trunk/src/org/openstreetmap/josm/data/projection/proj/TransverseMercator.java	(revision 13167)
@@ -5,6 +5,8 @@
 
 import org.openstreetmap.josm.data.Bounds;
+import org.openstreetmap.josm.data.coor.LatLon;
 import org.openstreetmap.josm.data.projection.ProjectionConfigurationException;
 import org.openstreetmap.josm.tools.CheckParameterUtil;
+import org.openstreetmap.josm.tools.Pair;
 import org.openstreetmap.josm.tools.Utils;
 
@@ -70,4 +72,12 @@
  */
 public class TransverseMercator extends AbstractProj {
+
+    /** Earth emispheres **/
+    public enum Hemisphere {
+        /** North emisphere */
+        North,
+        /** South emisphere */
+        South
+    }
 
     /**
@@ -223,3 +233,14 @@
         return new Bounds(-89, -7, 89, 7, false);
     }
+
+    /**
+     * Determines the UTM zone of a given lat/lon.
+     * @param ll lat/lon to locate in the UTM grid.
+     * @return the UTM zone of {@code ll}
+     * @since 13167
+     */
+    public static Pair<Integer, Hemisphere> locateUtmZone(LatLon ll) {
+        return new Pair<>((int) Math.floor((ll.lon() + 180d) / 6d) + 1,
+                ll.lat() > 0 ? Hemisphere.North : Hemisphere.South);
+    }
 }
Index: trunk/src/org/openstreetmap/josm/gui/dialogs/InspectPrimitiveDataText.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/InspectPrimitiveDataText.java	(revision 13165)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/InspectPrimitiveDataText.java	(revision 13167)
@@ -20,5 +20,8 @@
 import org.openstreetmap.josm.data.osm.RelationMember;
 import org.openstreetmap.josm.data.osm.Way;
+import org.openstreetmap.josm.data.projection.proj.TransverseMercator;
+import org.openstreetmap.josm.data.projection.proj.TransverseMercator.Hemisphere;
 import org.openstreetmap.josm.tools.Geometry;
+import org.openstreetmap.josm.tools.Pair;
 import org.openstreetmap.josm.tools.Utils;
 import org.openstreetmap.josm.tools.date.DateUtils;
@@ -212,7 +215,11 @@
                     Double.toString(n.lat()), ", ",
                     Double.toString(n.lon()));
+            EastNorth en = n.getEastNorth();
             add(tr("Coordinates (projected): "),
-                    Double.toString(n.getEastNorth().east()), ", ",
-                    Double.toString(n.getEastNorth().north()));
+                    Double.toString(en.east()), ", ",
+                    Double.toString(en.north()));
+            Pair<Integer, Hemisphere> utmZone = TransverseMercator.locateUtmZone(n.getCoor());
+            String utmLabel = tr("UTM Zone");
+            add(utmLabel, utmLabel.endsWith(":") ? " " : ": ", Integer.toString(utmZone.a), utmZone.b.toString().substring(0, 1));
         }
     }
Index: trunk/src/org/openstreetmap/josm/gui/preferences/projection/UTMProjectionChoice.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/preferences/projection/UTMProjectionChoice.java	(revision 13165)
+++ trunk/src/org/openstreetmap/josm/gui/preferences/projection/UTMProjectionChoice.java	(revision 13167)
@@ -16,4 +16,5 @@
 import javax.swing.JRadioButton;
 
+import org.openstreetmap.josm.data.projection.proj.TransverseMercator.Hemisphere;
 import org.openstreetmap.josm.tools.GBC;
 import org.openstreetmap.josm.tools.Logging;
@@ -25,12 +26,4 @@
  */
 public class UTMProjectionChoice extends ListProjectionChoice {
-
-    /** Earth emispheres **/
-    public enum Hemisphere {
-        /** North emisphere */
-        North,
-        /** South emisphere */
-        South
-    }
 
     private static final Hemisphere DEFAULT_HEMISPHERE = Hemisphere.North;