diff --git a/paimon-common/src/main/java/org/apache/paimon/types/InternalRowToSizeVisitor.java b/paimon-common/src/main/java/org/apache/paimon/types/InternalRowToSizeVisitor.java
index dbac55a07dde..721271ad1f8f 100644
--- a/paimon-common/src/main/java/org/apache/paimon/types/InternalRowToSizeVisitor.java
+++ b/paimon-common/src/main/java/org/apache/paimon/types/InternalRowToSizeVisitor.java
@@ -18,6 +18,8 @@
 
 package org.apache.paimon.types;
 
+import org.apache.paimon.data.Blob;
+import org.apache.paimon.data.BlobData;
 import org.apache.paimon.data.DataGetters;
 import org.apache.paimon.data.InternalArray;
 import org.apache.paimon.data.InternalMap;
@@ -229,7 +231,13 @@ public BiFunction<DataGetters, Integer, Integer> visit(BlobType blobType) {
             if (row.isNullAt(index)) {
                 return NULL_SIZE;
             } else {
-                return Math.toIntExact(row.getVariant(index).sizeInBytes());
+                Blob blob = row.getBlob(index);
+                if (blob instanceof BlobData) {
+                    return ((BlobData) blob).toData().length;
+                } else {
+                    // BlobRef and BlobView
+                    return Math.toIntExact(blob.toDescriptor().length());
+                }
             }
         };
     }
diff --git a/paimon-common/src/test/java/org/apache/paimon/types/InternalRowToSizeVisitorTest.java b/paimon-common/src/test/java/org/apache/paimon/types/InternalRowToSizeVisitorTest.java
index cfdae649c190..56bb18daad95 100644
--- a/paimon-common/src/test/java/org/apache/paimon/types/InternalRowToSizeVisitorTest.java
+++ b/paimon-common/src/test/java/org/apache/paimon/types/InternalRowToSizeVisitorTest.java
@@ -19,6 +19,7 @@
 package org.apache.paimon.types;
 
 import org.apache.paimon.data.BinaryString;
+import org.apache.paimon.data.Blob;
 import org.apache.paimon.data.DataGetters;
 import org.apache.paimon.data.Decimal;
 import org.apache.paimon.data.GenericArray;
@@ -192,4 +193,18 @@ void testCalculatorSize() {
 
         Assertions.assertThat(feildSizeCalculator.get(23).apply(row, 23)).isEqualTo(0);
     }
+
+    @Test
+    void testBlobSize() {
+        RowType rowType = RowType.builder().field("b", DataTypes.BLOB()).build();
+        InternalRowToSizeVisitor visitor = new InternalRowToSizeVisitor();
+        BiFunction<DataGetters, Integer, Integer> calculator =
+                rowType.getFieldTypes().get(0).accept(visitor);
+
+        GenericRow row = GenericRow.of(Blob.fromData(new byte[] {1, 2, 3}));
+        Assertions.assertThat(calculator.apply(row, 0)).isEqualTo(3);
+
+        GenericRow nullRow = GenericRow.of(new Object[] {null});
+        Assertions.assertThat(calculator.apply(nullRow, 0)).isEqualTo(0);
+    }
 }