diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java
index 41d13b7d264..047345c4687 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java
@@ -1748,6 +1748,7 @@ public class HRegionServer extends Thread implements
     int maxCompactedStoreFileRefCount = 0;
     int storeUncompressedSizeMB = 0;
     int storefileSizeMB = 0;
+    long storefileSizeByte = 0L;
     int memstoreSizeMB = (int) (r.getMemStoreDataSize() / 1024 / 1024);
     long storefileIndexSizeKB = 0;
     int rootLevelIndexSizeKB = 0;
@@ -1765,7 +1766,7 @@ public class HRegionServer extends Thread implements
       maxCompactedStoreFileRefCount = Math.max(maxCompactedStoreFileRefCount,
         currentMaxCompactedStoreFileRefCount);
       storeUncompressedSizeMB += (int) (store.getStoreSizeUncompressed() / 1024 / 1024);
-      storefileSizeMB += (int) (store.getStorefilesSize() / 1024 / 1024);
+      storefileSizeByte += store.getStorefilesSize();
       //TODO: storefileIndexSizeKB is same with rootLevelIndexSizeKB?
       storefileIndexSizeKB += store.getStorefilesRootLevelIndexSize() / 1024;
       CompactionProgress progress = store.getCompactionProgress();
@@ -1777,6 +1778,9 @@ public class HRegionServer extends Thread implements
       totalStaticIndexSizeKB += (int) (store.getTotalStaticIndexSize() / 1024);
       totalStaticBloomSizeKB += (int) (store.getTotalStaticBloomSize() / 1024);
     }
+    //HBASE-26340 Fix false "0" size under 1MB
+    storefileSizeMB = storefileSizeByte > 0 && storefileSizeByte <= 1024 * 1024
+       ? 1 : (int) storefileSizeByte / 1024 / 1024;
 
     HDFSBlocksDistribution hdfsBd = r.getHDFSBlocksDistribution();
     float dataLocality = hdfsBd.getBlockLocalityIndex(serverName.getHostname());