diff --git a/sources/qetgraphicsitem/masterelement.cpp b/sources/qetgraphicsitem/masterelement.cpp
index 1ccebfd3a..b9c829a0f 100644
--- a/sources/qetgraphicsitem/masterelement.cpp
+++ b/sources/qetgraphicsitem/masterelement.cpp
@@ -235,6 +235,28 @@ void MasterElement::aboutDeleteXref()
  * so they cannot disagree with each other.
  * @return the per type usage
  */
+namespace {
+
+	/**
+		Map the element data's contact type onto the tally's own, so that
+		the used count and the declared capacity cannot classify the same
+		contact type differently.
+	*/
+	ContactUsage::Type contactType(ElementData::SlaveState state)
+	{
+		switch (state)
+		{
+			case ElementData::NO:    return ContactUsage::NO;
+			case ElementData::NC:    return ContactUsage::NC;
+			case ElementData::SW:    return ContactUsage::SW;
+			case ElementData::Other: break;
+		}
+
+		return ContactUsage::Other;
+	}
+
+}
+
 ContactUsage MasterElement::contactUsage() const
 {
 	ContactUsage usage;
@@ -246,22 +268,32 @@ ContactUsage MasterElement::contactUsage() const
 		}
 
 		const ElementData &data = elmt->elementData();
-
-		ContactUsage::Type type = ContactUsage::Other;
-		switch (data.m_slave_state)
-		{
-			case ElementData::NO:    type = ContactUsage::NO;    break;
-			case ElementData::NC:    type = ContactUsage::NC;    break;
-			case ElementData::SW:    type = ContactUsage::SW;    break;
-			case ElementData::Other: type = ContactUsage::Other; break;
-		}
-
-		usage.addSlave(type, data.m_contact_count);
+		usage.addSlave(contactType(data.m_slave_state), data.m_contact_count);
 	}
 
 	return usage;
 }
 
+/**
+ * @brief MasterElement::contactCapacity
+ * The contacts this master declares it provides, by type, summed over its
+ * contact groups. A group stands for contactCount contacts of its type.
+ * Returns an empty tally when the element declares no groups, which is the
+ * case for every element in the standard collection today -- callers use
+ * that to decide whether a capacity is worth showing at all.
+ * @return the per type capacity
+ */
+ContactUsage MasterElement::contactCapacity() const
+{
+	ContactUsage capacity;
+
+	for (const auto &group : m_data.m_slave_contact_groups) {
+		capacity.addSlave(contactType(group.type), group.contactCount);
+	}
+
+	return capacity;
+}
+
 /**
  * @brief MasterElement::isFull
  * @return true if the master has reached its maximum number of slaves
diff --git a/sources/qetgraphicsitem/masterelement.h b/sources/qetgraphicsitem/masterelement.h
index 21aa20f40..2892e68e1 100644
--- a/sources/qetgraphicsitem/masterelement.h
+++ b/sources/qetgraphicsitem/masterelement.h
@@ -49,6 +49,7 @@ class MasterElement : public Element
 		QRectF XrefBoundingRect() const;
 
 		ContactUsage contactUsage() const;
+		ContactUsage contactCapacity() const;
 		bool isFull() const; // Check Slave-Limit
 		
 	protected:
diff --git a/sources/ui/elementpropertieswidget.cpp b/sources/ui/elementpropertieswidget.cpp
index 2dc75cd51..db6603663 100644
--- a/sources/ui/elementpropertieswidget.cpp
+++ b/sources/ui/elementpropertieswidget.cpp
@@ -393,16 +393,32 @@ QWidget *ElementPropertiesWidget::generalWidget()
 			//Counted in contacts rather than in linked elements, so that a
 			//slave standing for several contacts is reported as the number
 			//of contacts it actually uses.
-		const ContactUsage usage =
-				static_cast<MasterElement *>(m_element.data())->contactUsage();
+		const MasterElement *master =
+				static_cast<const MasterElement *>(m_element.data());
+		const ContactUsage usage = master->contactUsage();
 
 		description_string += QString(tr("Nombre de contacts esclaves utilisés : %1\n")).arg(usage.total());
 
 			//The breakdown is what tells you which auxiliary block would
 			//satisfy this coil, so it is only worth printing once there is
 			//something to break down.
-		if (usage.total() > 0)
+		const ContactUsage capacity = master->contactCapacity();
+
+		if (capacity.total() > 0)
 		{
+				//The element declares contact groups, so it can say not
+				//only what has been used but what it has to offer. A type
+				//used beyond what is declared shows as e.g. "1/0", which
+				//is the point: it says this contact does not fit the part.
+			description_string += QString(tr("    NO : %1/%2, NC : %3/%4, inverseurs : %5/%6, autres : %7/%8\n"))
+					.arg(usage.no).arg(capacity.no)
+					.arg(usage.nc).arg(capacity.nc)
+					.arg(usage.sw).arg(capacity.sw)
+					.arg(usage.other).arg(capacity.other);
+		}
+		else if (usage.total() > 0)
+		{
+				//No declared groups, so a plain count of what is in use.
 			description_string += QString(tr("    NO : %1, NC : %2, inverseurs : %3, autres : %4\n"))
 					.arg(usage.no)
 					.arg(usage.nc)
diff --git a/tests/qttest/tst_contactusage.cpp b/tests/qttest/tst_contactusage.cpp
index c587b3fbb..deb756933 100644
--- a/tests/qttest/tst_contactusage.cpp
+++ b/tests/qttest/tst_contactusage.cpp
@@ -101,6 +101,20 @@ private slots:
 		QCOMPARE(usage.total(), 1);
 	}
 
+	// A declared capacity is summed across groups, so two NO groups of two
+	// contacts each declare four NO contacts, not two groups.
+	void capacitySumsAcrossGroups()
+	{
+		ContactUsage capacity;
+		capacity.addSlave(ContactUsage::NO, 2);
+		capacity.addSlave(ContactUsage::NO, 2);
+		capacity.addSlave(ContactUsage::NC, 1);
+
+		QCOMPARE(capacity.no, 4);
+		QCOMPARE(capacity.nc, 1);
+		QCOMPARE(capacity.total(), 5);
+	}
+
 	// The mix a coil would actually carry: two single NO, one 4 pole NO,
 	// one NC and one changeover.
 	void tallysARealisticMix()