diff --git a/src/drc/drc/built-in-macros/_drc_layer.rb b/src/drc/drc/built-in-macros/_drc_layer.rb
index 646dc91cc..0411cbec9 100644
--- a/src/drc/drc/built-in-macros/_drc_layer.rb
+++ b/src/drc/drc/built-in-macros/_drc_layer.rb
@@ -276,16 +276,37 @@ module DRC
     end
     
     # %DRC%
-    # @name size 
+    # @name count 
     # @brief Returns the number of objects on the layer
-    # @synopsis layer.size
+    # @synopsis layer.count
     #
-    # The number of objects is the number of raw objects, not merged
-    # regions or edges. It is more efficent to call this method on output layers than
-    # on input layers.
+    # The count is the number of raw objects, not merged
+    # regions or edges. This is the flat count - the number of polygons,
+    # edges or edge pairs seen from the top cell.
+    # "count" can be computationally expensive for original layers with
+    # clip regions or cell tree filters.
+    #
+    # See \hier_count for a hierarchical (each cell counts once) count.
 
-    def size
-      self.data.size
+    def count
+      self.data.count
+    end
+    
+    # %DRC%
+    # @name hier_count 
+    # @brief Returns the hierarchical number of objects on the layer
+    # @synopsis layer.hier_count
+    #
+    # The hier_count is the number of raw objects, not merged
+    # regions or edges, with each cell counting once. 
+    # A high \count to hier_count (flat to hierarchical) ratio is an indication
+    # of a good hierarchical compression.
+    # "hier_count" applies only to original layers without clip regions or
+    # cell filters and to layers in \deep mode. Otherwise, hier_count gives 
+    # the same value than \count.
+
+    def hier_count
+      self.data.hier_count
     end
     
     # %DRC%
diff --git a/src/lay/lay/doc/about/drc_ref_layer.xml b/src/lay/lay/doc/about/drc_ref_layer.xml
index e7d077cd2..587180996 100644
--- a/src/lay/lay/doc/about/drc_ref_layer.xml
+++ b/src/lay/lay/doc/about/drc_ref_layer.xml
@@ -275,6 +275,21 @@ The following images show the effect of this method:
 </tr>
 </table>
 </p>
+<a name="count"/><h2>"count" - Returns the number of objects on the layer</h2>
+<keyword name="count"/>
+<p>Usage:</p>
+<ul>
+<li><tt>layer.count</tt></li>
+</ul>
+<p>
+The count is the number of raw objects, not merged
+regions or edges. This is the flat count - the number of polygons,
+edges or edge pairs seen from the top cell.
+"count" can be computationally expensive for original layers with
+clip regions or cell tree filters.
+</p><p>
+See <a href="#hier_count">hier_count</a> for a hierarchical (each cell counts once) count.
+</p>
 <a name="covering"/><h2>"covering" - Selects shapes or regions of self which completely cover (enclose) one or more shapes from the other region</h2>
 <keyword name="covering"/>
 <p>Usage:</p>
@@ -1187,6 +1202,21 @@ l = nil
 </p><p>
 By setting the layer to nil, it is ensured that it can no longer be accessed.
 </p>
+<a name="hier_count"/><h2>"hier_count" - Returns the hierarchical number of objects on the layer</h2>
+<keyword name="hier_count"/>
+<p>Usage:</p>
+<ul>
+<li><tt>layer.hier_count</tt></li>
+</ul>
+<p>
+The hier_count is the number of raw objects, not merged
+regions or edges, with each cell counting once. 
+A high <a href="#count">count</a> to hier_count (flat to hierarchical) ratio is an indication
+of a good hierarchical compression.
+"hier_count" applies only to original layers without clip regions or
+cell filters and to layers in <a href="#deep">deep</a> mode. Otherwise, hier_count gives 
+the same value than <a href="#count">count</a>.
+</p>
 <a name="holes"/><h2>"holes" - Selects all polygon holes from the input</h2>
 <keyword name="holes"/>
 <p>Usage:</p>
diff --git a/testdata/drc/drcSimpleTests_1.drc b/testdata/drc/drcSimpleTests_1.drc
index 28f5bd3a5..35e022c1d 100644
--- a/testdata/drc/drcSimpleTests_1.drc
+++ b/testdata/drc/drcSimpleTests_1.drc
@@ -3,7 +3,17 @@ dbu 0.001
 
 target($drc_test_target, "TOP")
 
+def self.expect_count(layer, c, hc, where)
+  if layer.count != c 
+    raise(where + ": Layer count #{layer.count} does not equal #{c}")
+  end
+  if layer.hier_count != hc 
+    raise(where + ": Layer hier count #{layer.hier_count} does not equal #{c}")
+  end
+end
+
 x = polygon_layer
+expect_count(x, 0, 0, "empty layer")
 x.is_empty? == true || raise("unexpected value")
 x.is_box? == false || raise("unexpected value")
 x.insert(box(4.0, 0, 4.7, 0.7))
@@ -12,6 +22,7 @@ x.is_box? == true || raise("unexpected value")
 x.insert(polygon([ p(0, 0), p(2.0, 0), p(1.0, 1.0) ]))
 x.insert(polygon([ p(0, -5.0), p(2.0, -5.0), p(1.0, -6.0) ]))
 x.insert(path([ p(0, -2), p(2.0, -2) ], 0.2))
+expect_count(x, 4, 4, "after 3x insert")
 x.is_box? == false || raise("unexpected value")
 x.output(10, 0)
 
diff --git a/testdata/drc/drcSimpleTests_2.drc b/testdata/drc/drcSimpleTests_2.drc
index 66faa4c55..d2055c458 100644
--- a/testdata/drc/drcSimpleTests_2.drc
+++ b/testdata/drc/drcSimpleTests_2.drc
@@ -2,6 +2,15 @@
 target($drc_test_target, "TOP")
 source($drc_test_source, "TOP")
 
+def self.expect_count(layer, c, hc, where)
+  if layer.count != c 
+    raise(where + ": Layer count #{layer.count} does not equal #{c}")
+  end
+  if layer.hier_count != hc 
+    raise(where + ": Layer hier count #{layer.hier_count} does not equal #{c}")
+  end
+end
+
 a1 = input(1)
 b1 = input(2)
 c1 = input(3)
@@ -89,3 +98,6 @@ a1.edges.collect_to_region { |p| p.length < 0.8 && p.bbox.transformed(RBA::VCplx
 a1.width(1.5).collect { |p| p.transformed(RBA::VCplxTrans::new(1000.0)) }.output(1120, 0)
 a1.width(1.5).collect_to_edge_pairs { |p| p.transformed(RBA::VCplxTrans::new(1000.0)) }.output(1121, 0)
 
+expect_count(a1.edges, 9, 9, "a1.edges")
+expect_count(a1.width(1.5), 5, 5, "a1.width(1.5)")
+
diff --git a/testdata/drc/drcSimpleTests_4.drc b/testdata/drc/drcSimpleTests_4.drc
index b729ee968..b05ecdcdc 100644
--- a/testdata/drc/drcSimpleTests_4.drc
+++ b/testdata/drc/drcSimpleTests_4.drc
@@ -4,6 +4,15 @@
 source($drc_test_source, "TOPTOP_SMALL")
 target($drc_test_target)
 
+def self.expect_count(layer, c, hc, where)
+  if layer.count != c 
+    raise(where + ": Layer count #{layer.count} does not equal #{c}")
+  end
+  if layer.hier_count != hc 
+    raise(where + ": Layer hier count #{layer.hier_count} does not equal #{c}")
+  end
+end
+
 cell("TOPTOP_SMALL")
 
 l1_flat = input(1)
@@ -66,12 +75,16 @@ r.output(1023, 0)
 r.extents.output(1123, 0)
 
 r = l1.space(0.5)
+expect_count(r, 3, 1, "r on l1")
 r.output(1010, 0)
 r.extents.output(1110, 0)
 
+expect_count(l1, 15, 5, "l1 before flatten")
 l1.flatten
+expect_count(l1, 15, 15, "l1 after flatten")
 r = l1.space(0.5)
 r.output(1011, 0)
 r.extents.output(1111, 0)
+expect_count(r, 3, 1, "r on l1.flatten")