diff --git a/zboxcore/sdk/chunked_upload.go b/zboxcore/sdk/chunked_upload.go
index 7c9d6628c..ab85ede34 100644
--- a/zboxcore/sdk/chunked_upload.go
+++ b/zboxcore/sdk/chunked_upload.go
@@ -206,8 +206,8 @@ func CreateChunkedUpload(
 	}
 
 	su.loadProgress()
-
-	su.fileHasher = CreateHasher(getShardSize(su.fileMeta.ActualSize, su.allocationObj.DataShards, su.encryptOnUpload))
+	su.shardSize = getShardSize(su.fileMeta.ActualSize, su.allocationObj.DataShards, su.encryptOnUpload)
+	su.fileHasher = CreateHasher(su.shardSize)
 
 	// encrypt option has been changed. upload it from scratch
 	// chunkSize has been changed. upload it from scratch
@@ -324,6 +324,8 @@ type ChunkedUpload struct {
 	shardUploadedSize int64
 	// shardUploadedThumbnailSize how much thumbnail bytes a shard has. it is original size
 	shardUploadedThumbnailSize int64
+	// size of shard
+	shardSize int64
 
 	// statusCallback trigger progress on StatusCallback
 	statusCallback StatusCallback
@@ -395,7 +397,7 @@ func (su *ChunkedUpload) createUploadProgress(connectionId string) {
 
 	for i := 0; i < len(su.progress.Blobbers); i++ {
 		su.progress.Blobbers[i] = &UploadBlobberStatus{
-			Hasher: CreateHasher(getShardSize(su.fileMeta.ActualSize, su.allocationObj.DataShards, su.encryptOnUpload)),
+			Hasher: CreateHasher(su.shardSize),
 		}
 	}
 
@@ -626,7 +628,6 @@ func (su *ChunkedUpload) readChunks(num int) (*batchChunksData, error) {
 func (su *ChunkedUpload) processUpload(chunkStartIndex, chunkEndIndex int,
 	fileShards []blobberShards, thumbnailShards blobberShards,
 	isFinal bool, uploadLength int64) error {
-
 	su.consensus.Reset()
 
 	ctx, cancel := context.WithCancel(context.TODO())
@@ -663,7 +664,7 @@ func (su *ChunkedUpload) processUpload(chunkStartIndex, chunkEndIndex int,
 			body, formData, err := su.formBuilder.Build(
 				&su.fileMeta, blobber.progress.Hasher, su.progress.ConnectionID,
 				su.chunkSize, chunkStartIndex, chunkEndIndex, isFinal, encryptedKey,
-				fileShards[pos], thumbnailChunkData)
+				fileShards[pos], thumbnailChunkData, su.shardSize)
 			if err != nil {
 				errC := atomic.AddInt32(&errCount, 1)
 				if errC > int32(su.allocationObj.ParityShards-1) { // If atleast data shards + 1 number of blobbers can process the upload, it can be repaired later
diff --git a/zboxcore/sdk/chunked_upload_form_builder.go b/zboxcore/sdk/chunked_upload_form_builder.go
index c8fa20fdf..55515b8f8 100644
--- a/zboxcore/sdk/chunked_upload_form_builder.go
+++ b/zboxcore/sdk/chunked_upload_form_builder.go
@@ -22,7 +22,7 @@ type ChunkedUploadFormBuilder interface {
 		fileMeta *FileMeta, hasher Hasher, connectionID string,
 		chunkSize int64, chunkStartIndex, chunkEndIndex int,
 		isFinal bool, encryptedKey string, fileChunksData [][]byte,
-		thumbnailChunkData []byte,
+		thumbnailChunkData []byte, shardSize int64,
 	) (*bytes.Buffer, ChunkedUploadFormMetadata, error)
 }
 
@@ -48,7 +48,7 @@ func (b *chunkedUploadFormBuilder) Build(
 	fileMeta *FileMeta, hasher Hasher, connectionID string,
 	chunkSize int64, chunkStartIndex, chunkEndIndex int,
 	isFinal bool, encryptedKey string, fileChunksData [][]byte,
-	thumbnailChunkData []byte,
+	thumbnailChunkData []byte, shardSize int64,
 ) (*bytes.Buffer, ChunkedUploadFormMetadata, error) {
 
 	metadata := ChunkedUploadFormMetadata{
@@ -78,6 +78,7 @@ func (b *chunkedUploadFormBuilder) Build(
 		ChunkStartIndex: chunkStartIndex,
 		ChunkEndIndex:   chunkEndIndex,
 		UploadOffset:    chunkSize * int64(chunkStartIndex),
+		Size:            shardSize,
 	}
 
 	formWriter := multipart.NewWriter(body)
diff --git a/zboxcore/sdk/chunked_upload_form_builder_bench_test.go b/zboxcore/sdk/chunked_upload_form_builder_bench_test.go
index d4fbcf1b9..25cea9953 100644
--- a/zboxcore/sdk/chunked_upload_form_builder_bench_test.go
+++ b/zboxcore/sdk/chunked_upload_form_builder_bench_test.go
@@ -68,7 +68,7 @@ func BenchmarkChunkedUploadFormBuilder(b *testing.B) {
 
 					fileBytes := buf[begin:end]
 
-					_, _, err := builder.Build(fileMeta, hasher, "connectionID", int64(bm.ChunkSize), chunkIndex, chunkIndex, isFinal, "", [][]byte{fileBytes}, nil)
+					_, _, err := builder.Build(fileMeta, hasher, "connectionID", int64(bm.ChunkSize), chunkIndex, chunkIndex, isFinal, "", [][]byte{fileBytes}, nil, getShardSize(fileMeta.ActualSize, 1, false))
 					if err != nil {
 						b.Fatal(err)
 						return
diff --git a/zboxcore/sdk/chunked_upload_model.go b/zboxcore/sdk/chunked_upload_model.go
index 1a7f96396..33bfd9d52 100644
--- a/zboxcore/sdk/chunked_upload_model.go
+++ b/zboxcore/sdk/chunked_upload_model.go
@@ -78,6 +78,7 @@ type UploadFormData struct {
 	ChunkEndIndex   int   `json:"chunk_end_index,omitempty"`   // end index of chunks. all chunks MUST be uploaded one by one because of streaming merkle hash
 	ChunkSize       int64 `json:"chunk_size,omitempty"`        // the size of a chunk. 64*1024 is default
 	UploadOffset    int64 `json:"upload_offset,omitempty"`     // It is next position that new incoming chunk should be append to
+	Size            int64 `json:"size"`                        // total size of shard
 
 }