diff --git a/blobstore/access/stream/stream.go b/blobstore/access/stream/stream.go
index cbe8af7fb..cba7b5bb9 100644
--- a/blobstore/access/stream/stream.go
+++ b/blobstore/access/stream/stream.go
@@ -533,11 +533,6 @@ func (h *Handler) punishShardnodeDisk(ctx context.Context, clusterID proto.Clust
 	}
 }
 
-// blobCount blobSize > 0 is certain
-func blobCount(size uint64, blobSize uint32) uint64 {
-	return (size + uint64(blobSize) - 1) / uint64(blobSize)
-}
-
 func errorTimeout(err error) bool {
 	msg := err.Error()
 	return strings.Contains(msg, "Timeout") || strings.Contains(msg, "timeout")
diff --git a/blobstore/access/stream/stream_alloc.go b/blobstore/access/stream/stream_alloc.go
index c70d7c1e6..8744da864 100644
--- a/blobstore/access/stream/stream_alloc.go
+++ b/blobstore/access/stream/stream_alloc.go
@@ -113,7 +113,7 @@ func (h *Handler) allocFromAllocator(ctx context.Context,
 	args := proxy.AllocVolsArgs{
 		Fsize:    size,
 		CodeMode: codeMode,
-		BidCount: blobCount(size, blobSize),
+		BidCount: util.AlignedBlocks(size, uint64(blobSize)),
 	}
 
 	var allocRets []proxy.AllocRet
@@ -183,7 +183,7 @@ func (h *Handler) allocFromAllocator(ctx context.Context,
 		setCacheVidHost(clusterID, ret.Vid, allocHost)
 	}
 
-	blobN := blobCount(size, blobSize)
+	blobN := util.AlignedBlocks(size, uint64(blobSize))
 	blobs := make([]proto.Slice, 0, blobN)
 	for _, bidRet := range allocRets {
 		if blobN <= 0 {
diff --git a/blobstore/common/crc32block/util.go b/blobstore/common/crc32block/util.go
index 8e481a391..c75c64ae8 100644
--- a/blobstore/common/crc32block/util.go
+++ b/blobstore/common/crc32block/util.go
@@ -58,7 +58,7 @@ func EncodeSize(size int64, blockLen int64) int64 {
 		panic(ErrInvalidBlock)
 	}
 	payload := BlockPayload(blockLen)
-	blockCnt := (size + (payload - 1)) / payload
+	blockCnt := util.AlignedBlocks(size, payload)
 	return size + crc32Len*blockCnt
 }
 
@@ -66,7 +66,7 @@ func DecodeSize(totalSize int64, blockLen int64) int64 {
 	if !isValidBlockLen(blockLen) {
 		panic(ErrInvalidBlock)
 	}
-	blockCnt := (totalSize + (blockLen - 1)) / blockLen
+	blockCnt := util.AlignedBlocks(totalSize, blockLen)
 	return totalSize - crc32Len*blockCnt
 }
 
diff --git a/blobstore/common/rpc2/checksum.go b/blobstore/common/rpc2/checksum.go
index 2cc1876f9..dbec59371 100644
--- a/blobstore/common/rpc2/checksum.go
+++ b/blobstore/common/rpc2/checksum.go
@@ -94,8 +94,7 @@ func (cb *ChecksumBlock) EncodeSize(originalSize int64) int64 {
 	if cb == nil || *cb == (ChecksumBlock{}) || originalSize == 0 {
 		return originalSize
 	}
-	payload := int64(cb.BlockSize)
-	blocks := (originalSize + (payload - 1)) / payload
+	blocks := util.AlignedBlocks(originalSize, int64(cb.BlockSize))
 	size := int64(algorithmSizes[cb.Algorithm])
 	if cb.Aligned {
 		size = _checksumAlignment
diff --git a/blobstore/util/alignment.go b/blobstore/util/alignment.go
index 08cfa4bd4..bc2c6612a 100644
--- a/blobstore/util/alignment.go
+++ b/blobstore/util/alignment.go
@@ -14,7 +14,10 @@
 
 package util
 
-import "unsafe"
+import (
+	"fmt"
+	"unsafe"
+)
 
 // AlignedBuffer address of first byte of buff wa aligned.
 // - - - - - - - - - - - - - - - - - - - -
@@ -34,10 +37,36 @@ func AlignedBuffer(head, capacity, alignment int) []byte {
 
 // AlignedHead head with alignment.
 func AlignedHead[I Integer](size, alignment I) I {
+	assert(size, alignment)
 	return size % alignment
 }
 
 // AlignedTail tail with alignment.
 func AlignedTail[I Integer](size, alignment I) I {
+	assert(size, alignment)
 	return (alignment - size%alignment) % alignment
 }
+
+// AlignedFull full with alignment.
+func AlignedFull[I Integer](size, alignment I) I {
+	assert(size, alignment)
+	if (alignment & (alignment - 1)) == 0 {
+		return (size + (alignment - 1)) & (^(alignment - 1))
+	}
+	return AlignedBlocks(size, alignment) * alignment
+}
+
+// AlignedBlocks number of blocks with alignment.
+func AlignedBlocks[I Integer](size, alignment I) I {
+	assert(size, alignment)
+	return (size + (alignment - 1)) / alignment
+}
+
+func assert[I Integer](size, alignment I) {
+	if size < 0 {
+		panic(fmt.Sprintf("util-align: size(%d) < 0", size))
+	}
+	if alignment <= 0 {
+		panic(fmt.Sprintf("util-align: alignment(%d) <= 0", alignment))
+	}
+}
diff --git a/blobstore/util/alignment_test.go b/blobstore/util/alignment_test.go
index 962765553..ac3aa23cf 100644
--- a/blobstore/util/alignment_test.go
+++ b/blobstore/util/alignment_test.go
@@ -38,6 +38,10 @@ func TestUtilAlignmentBuffer(t *testing.T) {
 }
 
 func TestUtilAlignmentHeadTail(t *testing.T) {
+	require.Panics(t, func() { AlignedHead(-1, 128) })
+	require.Panics(t, func() { AlignedHead(1, 0) })
+	require.Panics(t, func() { AlignedTail(-1, 128) })
+	require.Panics(t, func() { AlignedTail(1, 0) })
 	require.Equal(t, 0, AlignedHead(0, 128))
 	require.Equal(t, int64(1), AlignedHead[int64](513, 512))
 	require.Equal(t, uint64(0), AlignedTail[uint64](512, 512))
@@ -57,3 +61,46 @@ func TestUtilAlignmentHeadTail(t *testing.T) {
 		}
 	}
 }
+
+func TestUtilAlignmentBlock(t *testing.T) {
+	require.Equal(t, 0, AlignedFull(0, 128))
+	require.Equal(t, 0, AlignedBlocks(0, 128))
+	require.Equal(t, int64(1024), AlignedFull[int64](513, 512))
+	require.Equal(t, int64(2), AlignedBlocks[int64](513, 512))
+	require.Equal(t, uint64(512), AlignedFull[uint64](512, 512))
+	require.Equal(t, uint64(1), AlignedBlocks[uint64](512, 512))
+	for range [100]struct{}{} {
+		size := rand.Int63() + 1
+		alignment := int64(32 << 10)
+		if rand.Int63()%7 == 0 {
+			size -= size % alignment
+		}
+		full := AlignedFull(size, alignment)
+		blocks := AlignedBlocks(size, alignment)
+		require.Equal(t, full, blocks*alignment)
+		if tail := AlignedTail(size, alignment); tail == 0 {
+			require.Equal(t, size, full)
+			require.Equal(t, size/alignment, blocks)
+		} else {
+			require.Equal(t, size+tail, full)
+			require.Equal(t, size/alignment+1, blocks)
+		}
+	}
+	for range [100]struct{}{} {
+		size := rand.Int63() + 1
+		alignment := rand.Int63n(1<<20) + 1
+		if rand.Int63()%7 == 0 {
+			size -= size % alignment
+		}
+		full := AlignedFull(size, alignment)
+		blocks := AlignedBlocks(size, alignment)
+		require.Equal(t, full, blocks*alignment)
+		if tail := AlignedTail(size, alignment); tail == 0 {
+			require.Equal(t, size, full)
+			require.Equal(t, size/alignment, blocks)
+		} else {
+			require.Equal(t, size+tail, full)
+			require.Equal(t, size/alignment+1, blocks)
+		}
+	}
+}