diff --git a/ethdb/leveldb/leveldb.go b/ethdb/leveldb/leveldb.go
index 9ff1a2ce1d68..9a782dedbe14 100644
--- a/ethdb/leveldb/leveldb.go
+++ b/ethdb/leveldb/leveldb.go
@@ -455,7 +455,7 @@ type batch struct {
 // Put inserts the given value into the batch for later committing.
 func (b *batch) Put(key, value []byte) error {
 	b.b.Put(key, value)
-	b.size += len(value)
+	b.size += len(key) + len(value)
 	return nil
 }
 
diff --git a/ethdb/memorydb/memorydb.go b/ethdb/memorydb/memorydb.go
index fedc9e326cf8..78181e860c15 100644
--- a/ethdb/memorydb/memorydb.go
+++ b/ethdb/memorydb/memorydb.go
@@ -204,7 +204,7 @@ type batch struct {
 // Put inserts the given value into the batch for later committing.
 func (b *batch) Put(key, value []byte) error {
 	b.writes = append(b.writes, keyvalue{common.CopyBytes(key), common.CopyBytes(value), false})
-	b.size += len(value)
+	b.size += len(key) + len(value)
 	return nil
 }