diff --git a/tsdb/head.go b/tsdb/head.go
index 7763d272b7..c2a1dc0c0e 100644
--- a/tsdb/head.go
+++ b/tsdb/head.go
@@ -62,6 +62,8 @@ var (
 	defaultIsolationDisabled = false
 
 	defaultWALReplayConcurrency = runtime.GOMAXPROCS(0)
+
+	compactibleRatio = 1.1
 )
 
 // Head handles reads and writes of time series data within a time window.
@@ -1700,7 +1702,7 @@ func (h *Head) compactable() bool {
 		return false
 	}
 
-	return h.MaxTime()-h.MinTime() > h.chunkRange.Load()/2*3
+	return h.MaxTime()-h.MinTime() > int64(float64(h.chunkRange.Load())*compactibleRatio)
 }
 
 // Close flushes the WAL and closes the head.
diff --git a/tsdb/head_append.go b/tsdb/head_append.go
index 03800b2455..4a680f4d03 100644
--- a/tsdb/head_append.go
+++ b/tsdb/head_append.go
@@ -194,7 +194,7 @@ func (h *Head) appender() *headAppender {
 func (h *Head) appendableMinValidTime() int64 {
 	// This boundary ensures that no samples will be added to the compaction window.
 	// This allows race-free, concurrent appending and compaction.
-	cwEnd := h.MaxTime() - h.chunkRange.Load()/2
+	cwEnd := h.MaxTime() - int64(float64(h.chunkRange.Load())*(compactibleRatio-1))
 
 	// This boundary ensures that we avoid overlapping timeframes from one block to the next.
 	// While not necessary for correctness, it means we're not required to use vertical compaction.