diff --git a/pkg/writers/buffer/buffer.go b/pkg/writers/buffer/buffer.go
index b28b47bfa..15dacff96 100644
--- a/pkg/writers/buffer/buffer.go
+++ b/pkg/writers/buffer/buffer.go
@@ -23,7 +23,7 @@ func (poolMetrics) recordBufferRetrival() {
 
 func (poolMetrics) recordBufferReturn(buf *Buffer) {
 	activeBufferCount.Dec()
-	totalBufferSize.Add(float64(buf.Len()))
+	totalBufferSize.Add(float64(buf.Cap()))
 	totalBufferLength.Add(float64(buf.Len()))
 	buf.recordMetric()
 }
diff --git a/pkg/writers/buffer_writer/bufferwriter.go b/pkg/writers/buffer_writer/bufferwriter.go
index 6a564f4de..8f0122223 100644
--- a/pkg/writers/buffer_writer/bufferwriter.go
+++ b/pkg/writers/buffer_writer/bufferwriter.go
@@ -62,8 +62,7 @@ func (b *BufferWriter) Write(data []byte) (int, error) {
 	b.size += size
 	start := time.Now()
 	defer func(start time.Time) {
-		bufferLength := int64(b.buf.Len())
-		b.metrics.recordDataProcessed(bufferLength, time.Since(start))
+		b.metrics.recordDataProcessed(int64(size), time.Since(start))
 
 	}(start)
 	return b.buf.Write(data)