diff --git a/src/main/java/org/opensearch/knn/index/codec/util/KNNCodecUtil.java b/src/main/java/org/opensearch/knn/index/codec/util/KNNCodecUtil.java
index 554d5cb39..c22131030 100644
--- a/src/main/java/org/opensearch/knn/index/codec/util/KNNCodecUtil.java
+++ b/src/main/java/org/opensearch/knn/index/codec/util/KNNCodecUtil.java
@@ -97,27 +97,26 @@ public static long calculateArraySize(int numVectors, int vectorLength, Serializ
         // For more details on array memory usage in Java, visit https://www.javamex.com/tutorials/memory/array_memory_usage.shtml
         if (serializationMode == SerializationMode.ARRAY) {
             int vectorSize = vectorLength * FLOAT_BYTE_SIZE + JAVA_ARRAY_HEADER_SIZE;
-            if (vectorSize % JAVA_ROUNDING_NUMBER != 0) {
-                vectorSize += (JAVA_ROUNDING_NUMBER - vectorSize % JAVA_ROUNDING_NUMBER);
-            }
+            vectorSize = roundVectorSize(vectorSize);
             int vectorsSize = numVectors * (vectorSize + JAVA_REFERENCE_SIZE) + JAVA_ARRAY_HEADER_SIZE;
-            if (vectorsSize % JAVA_ROUNDING_NUMBER != 0) {
-                vectorsSize += (JAVA_ROUNDING_NUMBER - vectorsSize % JAVA_ROUNDING_NUMBER);
-            }
+            vectorsSize = roundVectorSize(vectorsSize);
             return vectorsSize;
         } else {
             int vectorSize = vectorLength * FLOAT_BYTE_SIZE;
-            if (vectorSize % JAVA_ROUNDING_NUMBER != 0) {
-                vectorSize += (JAVA_ROUNDING_NUMBER - vectorSize % JAVA_ROUNDING_NUMBER);
-            }
+            vectorSize = roundVectorSize(vectorSize);
             int vectorsSize = numVectors * (vectorSize + JAVA_REFERENCE_SIZE);
-            if (vectorsSize % JAVA_ROUNDING_NUMBER != 0) {
-                vectorsSize += (JAVA_ROUNDING_NUMBER - vectorsSize % JAVA_ROUNDING_NUMBER);
-            }
+            vectorsSize = roundVectorSize(vectorsSize);
             return vectorsSize;
         }
     }
 
+    private static int roundVectorSize(int vectorSize) {
+        if (vectorSize % JAVA_ROUNDING_NUMBER != 0) {
+            return vectorSize + (JAVA_ROUNDING_NUMBER - vectorSize % JAVA_ROUNDING_NUMBER);
+        }
+        return vectorSize;
+    }
+
     public static String buildEngineFileName(String segmentName, String latestBuildVersion, String fieldName, String extension) {
         return String.format("%s%s%s", buildEngineFilePrefix(segmentName), latestBuildVersion, buildEngineFileSuffix(fieldName, extension));
     }
diff --git a/src/test/java/org/opensearch/knn/index/codec/KNN80Codec/KNN80DocValuesConsumerTests.java b/src/test/java/org/opensearch/knn/index/codec/KNN80Codec/KNN80DocValuesConsumerTests.java
index f7c9f3eb8..58927e9ac 100644
--- a/src/test/java/org/opensearch/knn/index/codec/KNN80Codec/KNN80DocValuesConsumerTests.java
+++ b/src/test/java/org/opensearch/knn/index/codec/KNN80Codec/KNN80DocValuesConsumerTests.java
@@ -192,6 +192,7 @@ public void testAddKNNBinaryField_fromScratch_nmslibCurrent() throws IOException
 
         long initialRefreshOperations = KNNGraphValue.REFRESH_TOTAL_OPERATIONS.getValue();
         long initialMergeOperations = KNNGraphValue.MERGE_TOTAL_OPERATIONS.getValue();
+        long initialMergeTotalSize = KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue();
 
         // Add documents to the field
         KNN80DocValuesConsumer knn80DocValuesConsumer = new KNN80DocValuesConsumer(null, state);
@@ -212,7 +213,7 @@ public void testAddKNNBinaryField_fromScratch_nmslibCurrent() throws IOException
         assertEquals(1 + initialRefreshOperations, (long) KNNGraphValue.REFRESH_TOTAL_OPERATIONS.getValue());
         assertEquals(1 + initialMergeOperations, (long) KNNGraphValue.MERGE_TOTAL_OPERATIONS.getValue());
         assertNotEquals(0, (long) KNNGraphValue.MERGE_TOTAL_DOCS.getValue());
-        assertNotEquals(0, (long) KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue());
+        assertEquals(initialMergeTotalSize + 6800, (long) KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue());
     }
 
     public void testAddKNNBinaryField_fromScratch_nmslibLegacy() throws IOException {
@@ -245,6 +246,7 @@ public void testAddKNNBinaryField_fromScratch_nmslibLegacy() throws IOException
 
         long initialRefreshOperations = KNNGraphValue.REFRESH_TOTAL_OPERATIONS.getValue();
         long initialMergeOperations = KNNGraphValue.MERGE_TOTAL_OPERATIONS.getValue();
+        long initialMergeTotalSize = KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue();
 
         // Add documents to the field
         KNN80DocValuesConsumer knn80DocValuesConsumer = new KNN80DocValuesConsumer(null, state);
@@ -265,7 +267,7 @@ public void testAddKNNBinaryField_fromScratch_nmslibLegacy() throws IOException
         assertEquals(1 + initialRefreshOperations, (long) KNNGraphValue.REFRESH_TOTAL_OPERATIONS.getValue());
         assertEquals(1 + initialMergeOperations, (long) KNNGraphValue.MERGE_TOTAL_OPERATIONS.getValue());
         assertNotEquals(0, (long) KNNGraphValue.MERGE_TOTAL_DOCS.getValue());
-        assertNotEquals(0, (long) KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue());
+        assertEquals(initialMergeTotalSize + 6800, (long) KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue());
     }
 
     public void testAddKNNBinaryField_fromScratch_faissCurrent() throws IOException {
@@ -306,6 +308,7 @@ public void testAddKNNBinaryField_fromScratch_faissCurrent() throws IOException
 
         long initialRefreshOperations = KNNGraphValue.REFRESH_TOTAL_OPERATIONS.getValue();
         long initialMergeOperations = KNNGraphValue.MERGE_TOTAL_OPERATIONS.getValue();
+        long initialMergeTotalSize = KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue();
 
         // Add documents to the field
         KNN80DocValuesConsumer knn80DocValuesConsumer = new KNN80DocValuesConsumer(null, state);
@@ -326,7 +329,7 @@ public void testAddKNNBinaryField_fromScratch_faissCurrent() throws IOException
         assertEquals(1 + initialRefreshOperations, (long) KNNGraphValue.REFRESH_TOTAL_OPERATIONS.getValue());
         assertEquals(1 + initialMergeOperations, (long) KNNGraphValue.MERGE_TOTAL_OPERATIONS.getValue());
         assertNotEquals(0, (long) KNNGraphValue.MERGE_TOTAL_DOCS.getValue());
-        assertNotEquals(0, (long) KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue());
+        assertEquals(initialMergeTotalSize + 6800, (long) KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue());
     }
 
     public void testAddKNNBinaryField_fromModel_faiss() throws IOException, ExecutionException, InterruptedException {
@@ -401,6 +404,7 @@ public void testAddKNNBinaryField_fromModel_faiss() throws IOException, Executio
 
         long initialRefreshOperations = KNNGraphValue.REFRESH_TOTAL_OPERATIONS.getValue();
         long initialMergeOperations = KNNGraphValue.MERGE_TOTAL_OPERATIONS.getValue();
+        long initialMergeTotalSize = KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue();
 
         // Add documents to the field
         KNN80DocValuesConsumer knn80DocValuesConsumer = new KNN80DocValuesConsumer(null, state);
@@ -421,7 +425,7 @@ public void testAddKNNBinaryField_fromModel_faiss() throws IOException, Executio
         assertEquals(1 + initialRefreshOperations, (long) KNNGraphValue.REFRESH_TOTAL_OPERATIONS.getValue());
         assertEquals(1 + initialMergeOperations, (long) KNNGraphValue.MERGE_TOTAL_OPERATIONS.getValue());
         assertNotEquals(0, (long) KNNGraphValue.MERGE_TOTAL_DOCS.getValue());
-        assertNotEquals(0, (long) KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue());
+        assertEquals(initialMergeTotalSize + 6800, (long) KNNGraphValue.MERGE_TOTAL_SIZE_IN_BYTES.getValue());
 
     }