diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
index e9b4af9..945900f 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackTest.java
@@ -1060,6 +1060,67 @@
 	}
 
 	@Test
+	public void testUploadNewBytes() throws Exception {
+		String commonInBlob = "abcdefghijklmnopqrstuvwx";
+
+		RevBlob parentBlob = remote.blob(commonInBlob + "a");
+		RevCommit parent = remote.commit(remote.tree(remote.file("foo", parentBlob)));
+		RevBlob childBlob = remote.blob(commonInBlob + "b");
+		RevCommit child = remote.commit(remote.tree(remote.file("foo", childBlob)), parent);
+		remote.update("branch1", child);
+
+		ByteArrayInputStream recvStream = uploadPackV2(
+			"command=fetch\n",
+			PacketLineIn.delimiter(),
+			"want " + child.toObjectId().getName() + "\n",
+			"ofs-delta\n",
+			"done\n",
+				PacketLineIn.end());
+		PacketLineIn pckIn = new PacketLineIn(recvStream);
+		assertThat(pckIn.readString(), is("packfile"));
+		ReceivedPackStatistics receivedStats = parsePack(recvStream);
+		assertTrue(receivedStats.getNumBytesDuplicated() == 0);
+		assertTrue(receivedStats.getNumObjectsDuplicated() == 0);
+	}
+
+	@Test
+	public void testUploadRedundantBytes() throws Exception {
+		String commonInBlob = "abcdefghijklmnopqrstuvwxyz";
+
+		RevBlob parentBlob = remote.blob(commonInBlob + "a");
+		RevCommit parent = remote.commit(remote.tree(remote.file("foo", parentBlob)));
+		RevBlob childBlob = remote.blob(commonInBlob + "b");
+		RevCommit child = remote.commit(remote.tree(remote.file("foo", childBlob)), parent);
+		remote.update("branch1", child);
+
+		TestRepository<InMemoryRepository> local = new TestRepository<>(client);
+		RevBlob localParentBlob = local.blob(commonInBlob + "a");
+		RevCommit localParent = local.commit(local.tree(local.file("foo", localParentBlob)));
+		RevBlob localChildBlob = local.blob(commonInBlob + "b");
+		RevCommit localChild = local.commit(
+				local.tree(local.file("foo", localChildBlob)), localParent);
+		local.update("branch1", localChild);
+
+		ByteArrayInputStream recvStream = uploadPackV2(
+				"command=fetch\n",
+				PacketLineIn.delimiter(),
+				"want " + child.toObjectId().getName() + "\n",
+				"ofs-delta\n",
+				"done\n",
+					PacketLineIn.end());
+		PacketLineIn pckIn = new PacketLineIn(recvStream);
+		assertThat(pckIn.readString(), is("packfile"));
+		ReceivedPackStatistics receivedStats = parsePack(recvStream);
+
+		long sizeOfHeader = 12;
+		long sizeOfTrailer = 20;
+		long expectedSize = receivedStats.getNumBytesRead() - sizeOfHeader
+				- sizeOfTrailer;
+		assertTrue(receivedStats.getNumBytesDuplicated() == expectedSize);
+		assertTrue(receivedStats.getNumObjectsDuplicated() == 6);
+	}
+
+	@Test
 	public void testV2FetchOfsDelta() throws Exception {
 		String commonInBlob = "abcdefghijklmnopqrstuvwxyz";
 
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/PackParser.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/PackParser.java
index 0801b8a..715cbb4 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/PackParser.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/PackParser.java
@@ -679,7 +679,8 @@
 
 			verifySafeObject(tempObjectId, type, visit.data);
 			if (isCheckObjectCollisions() && readCurs.has(tempObjectId)) {
-				checkObjectCollision(tempObjectId, type, visit.data);
+				checkObjectCollision(tempObjectId, type, visit.data,
+						visit.delta.sizeBeforeInflating);
 			}
 
 			PackedObjectInfo oe;
@@ -999,6 +1000,7 @@
 			UnresolvedDelta n = onEndDelta();
 			n.position = streamPosition;
 			n.next = baseByPos.put(base, n);
+			n.sizeBeforeInflating = streamPosition() - streamPosition;
 			deltaCount++;
 			break;
 		}
@@ -1020,6 +1022,7 @@
 			inflateAndSkip(Source.INPUT, sz);
 			UnresolvedDelta n = onEndDelta();
 			n.position = streamPosition;
+			n.sizeBeforeInflating = streamPosition() - streamPosition;
 			r.add(n);
 			deltaCount++;
 			break;
@@ -1071,9 +1074,11 @@
 			verifySafeObject(tempObjectId, type, data);
 		}
 
+		long sizeBeforeInflating = streamPosition() - pos;
 		PackedObjectInfo obj = newInfo(tempObjectId, null, null);
 		obj.setOffset(pos);
 		obj.setType(type);
+		obj.setSize(sizeBeforeInflating);
 		onEndWholeObject(obj);
 		if (data != null)
 			onInflatedObjectData(obj, type, data);
@@ -1148,6 +1153,8 @@
 					sz -= n;
 				}
 			}
+			stats.incrementObjectsDuplicated();
+			stats.incrementNumBytesDuplicated(obj.getSize());
 		} catch (MissingObjectException notLocal) {
 			// This is OK, we don't have a copy of the object locally
 			// but the API throws when we try to read it as usually it's
@@ -1155,15 +1162,17 @@
 		}
 	}
 
-	private void checkObjectCollision(AnyObjectId obj, int type, byte[] data)
-			throws IOException {
+	private void checkObjectCollision(AnyObjectId obj, int type, byte[] data,
+			long sizeBeforeInflating) throws IOException {
 		try {
 			final ObjectLoader ldr = readCurs.open(obj, type);
 			final byte[] existingData = ldr.getCachedBytes(data.length);
 			if (!Arrays.equals(data, existingData)) {
-				throw new IOException(MessageFormat.format(
-						JGitText.get().collisionOn, obj.name()));
+				throw new IOException(MessageFormat
+						.format(JGitText.get().collisionOn, obj.name()));
 			}
+			stats.incrementObjectsDuplicated();
+			stats.incrementNumBytesDuplicated(sizeBeforeInflating);
 		} catch (MissingObjectException notLocal) {
 			// This is OK, we don't have a copy of the object locally
 			// but the API throws when we try to read it as usually its
@@ -1653,6 +1662,8 @@
 
 		UnresolvedDelta next;
 
+		long sizeBeforeInflating;
+
 		/** @return offset within the input stream. */
 		public long getOffset() {
 			return position;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/PackedObjectInfo.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/PackedObjectInfo.java
index fc906de..fe1209b 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/PackedObjectInfo.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/PackedObjectInfo.java
@@ -29,6 +29,8 @@
 
 	private int type = Constants.OBJ_BAD;
 
+	private long sizeBeforeInflating;
+
 	PackedObjectInfo(final long headerOffset, final int packedCRC,
 			final AnyObjectId id) {
 		super(id);
@@ -108,4 +110,12 @@
 	public void setType(int type) {
 		this.type = type;
 	}
+
+	void setSize(long sizeBeforeInflating) {
+		this.sizeBeforeInflating = sizeBeforeInflating;
+	}
+
+	long getSize() {
+		return sizeBeforeInflating;
+	}
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivedPackStatistics.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivedPackStatistics.java
index bd8f558..d7bc400 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivedPackStatistics.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivedPackStatistics.java
@@ -19,6 +19,7 @@
  */
 public class ReceivedPackStatistics {
 	private long numBytesRead;
+	private long numBytesDuplicated;
 
 	private long numWholeCommit;
 	private long numWholeTree;
@@ -26,6 +27,7 @@
 	private long numWholeTag;
 	private long numOfsDelta;
 	private long numRefDelta;
+	private long numObjectsDuplicated;
 
 	private long numDeltaCommit;
 	private long numDeltaTree;
@@ -42,6 +44,17 @@
 	}
 
 	/**
+	 * Get number of bytes of objects already in the local database
+	 *
+	 * @return number of bytes of objects appeared in both the pack sent by the
+	 *         client and the local database
+	 * @since 5.10
+	 */
+	public long getNumBytesDuplicated() {
+		return numBytesDuplicated;
+	}
+
+	/**
 	 * Get number of whole commit objects in the pack
 	 *
 	 * @return number of whole commit objects in the pack
@@ -96,6 +109,17 @@
 	}
 
 	/**
+	 * Get number of objects already in the local database
+	 *
+	 * @return number of objects appeared in both the pack sent by the client
+	 *         and the local database
+	 * @since 5.10
+	 */
+	public long getNumObjectsDuplicated() {
+		return numObjectsDuplicated;
+	}
+
+	/**
 	 * Get number of delta commit objects in the pack
 	 *
 	 * @return number of delta commit objects in the pack
@@ -134,6 +158,7 @@
 	/** A builder for {@link ReceivedPackStatistics}. */
 	public static class Builder {
 		private long numBytesRead;
+		private long numBytesDuplicated;
 
 		private long numWholeCommit;
 		private long numWholeTree;
@@ -141,6 +166,7 @@
 		private long numWholeTag;
 		private long numOfsDelta;
 		private long numRefDelta;
+		private long numObjectsDuplicated;
 
 		private long numDeltaCommit;
 		private long numDeltaTree;
@@ -157,6 +183,17 @@
 		}
 
 		/**
+		 * @param size
+		 *            additional bytes already in the local database
+		 * @return this
+		 * @since 5.10
+		 */
+		Builder incrementNumBytesDuplicated(long size) {
+			numBytesDuplicated += size;
+			return this;
+		}
+
+		/**
 		 * Increment a whole object count.
 		 *
 		 * @param type OBJ_COMMIT, OBJ_TREE, OBJ_BLOB, or OBJ_TAG
@@ -196,6 +233,17 @@
 		}
 
 		/**
+		 * Increment the duplicated object count.
+		 *
+		 * @return this
+		 * @since 5.10
+		 */
+		Builder incrementObjectsDuplicated() {
+			numObjectsDuplicated++;
+			return this;
+		}
+
+		/**
 		 * Increment a delta object count.
 		 *
 		 * @param type OBJ_COMMIT, OBJ_TREE, OBJ_BLOB, or OBJ_TAG
@@ -226,6 +274,7 @@
 		ReceivedPackStatistics build() {
 			ReceivedPackStatistics s = new ReceivedPackStatistics();
 			s.numBytesRead = numBytesRead;
+			s.numBytesDuplicated = numBytesDuplicated;
 			s.numWholeCommit = numWholeCommit;
 			s.numWholeTree = numWholeTree;
 			s.numWholeBlob = numWholeBlob;
@@ -236,6 +285,7 @@
 			s.numDeltaTree = numDeltaTree;
 			s.numDeltaBlob = numDeltaBlob;
 			s.numDeltaTag = numDeltaTag;
+			s.numObjectsDuplicated = numObjectsDuplicated;
 			return s;
 		}
 	}