diff --git a/pkg/ingester/metrics.go b/pkg/ingester/metrics.go
index 585cc45df94..cdea01c0c41 100644
--- a/pkg/ingester/metrics.go
+++ b/pkg/ingester/metrics.go
@@ -349,6 +349,7 @@ type tsdbMetrics struct {
 	tsdbHeadTruncateFail         *prometheus.Desc
 	tsdbHeadTruncateTotal        *prometheus.Desc
 	tsdbHeadGcDuration           *prometheus.Desc
+	tsdbHeadSeries               *prometheus.Desc
 	tsdbActiveAppenders          *prometheus.Desc
 	tsdbSeriesNotFound           *prometheus.Desc
 	tsdbChunks                   *prometheus.Desc
@@ -454,6 +455,10 @@ func newTSDBMetrics(r prometheus.Registerer) *tsdbMetrics {
 			"cortex_ingester_tsdb_head_gc_duration_seconds",
 			"Runtime of garbage collection in the TSDB head.",
 			nil, nil),
+		tsdbHeadSeries: prometheus.NewDesc(
+			"cortex_ingester_tsdb_head_series",
+			"Total number of series in the TSDB head block.",
+			[]string{"user"}, nil),
 		tsdbActiveAppenders: prometheus.NewDesc(
 			"cortex_ingester_tsdb_head_active_appenders",
 			"Number of currently active TSDB appender transactions.",
@@ -573,6 +578,7 @@ func (sm *tsdbMetrics) Describe(out chan<- *prometheus.Desc) {
 	out <- sm.tsdbHeadTruncateFail
 	out <- sm.tsdbHeadTruncateTotal
 	out <- sm.tsdbHeadGcDuration
+	out <- sm.tsdbHeadSeries
 	out <- sm.tsdbActiveAppenders
 	out <- sm.tsdbSeriesNotFound
 	out <- sm.tsdbChunks
@@ -622,6 +628,7 @@ func (sm *tsdbMetrics) Collect(out chan<- prometheus.Metric) {
 	data.SendSumOfCounters(out, sm.tsdbHeadTruncateFail, "prometheus_tsdb_head_truncations_failed_total")
 	data.SendSumOfCounters(out, sm.tsdbHeadTruncateTotal, "prometheus_tsdb_head_truncations_total")
 	data.SendSumOfSummaries(out, sm.tsdbHeadGcDuration, "prometheus_tsdb_head_gc_duration_seconds")
+	data.SendSumOfGaugesPerUser(out, sm.tsdbHeadSeries, "prometheus_tsdb_head_series")
 	data.SendSumOfGauges(out, sm.tsdbActiveAppenders, "prometheus_tsdb_head_active_appenders")
 	data.SendSumOfCounters(out, sm.tsdbSeriesNotFound, "prometheus_tsdb_head_series_not_found_total")
 	data.SendSumOfGauges(out, sm.tsdbChunks, "prometheus_tsdb_head_chunks")
diff --git a/pkg/ingester/metrics_test.go b/pkg/ingester/metrics_test.go
index c60e0ae6e24..d62b8c064e2 100644
--- a/pkg/ingester/metrics_test.go
+++ b/pkg/ingester/metrics_test.go
@@ -139,6 +139,13 @@ func TestTSDBMetrics(t *testing.T) {
 			# TYPE cortex_ingester_tsdb_head_active_appenders gauge
 			cortex_ingester_tsdb_head_active_appenders 1982620
 
+			# HELP cortex_ingester_tsdb_head_series Total number of series in the TSDB head block.
+			# TYPE cortex_ingester_tsdb_head_series gauge
+			# 20 * (12345 and 85787 and 999 respectively)
+			cortex_ingester_tsdb_head_series{user="user1"} 246900
+			cortex_ingester_tsdb_head_series{user="user2"} 1715740
+			cortex_ingester_tsdb_head_series{user="user3"} 19980
+
 			# HELP cortex_ingester_tsdb_head_series_not_found_total Total number of TSDB requests for series that were not found.
 			# TYPE cortex_ingester_tsdb_head_series_not_found_total counter
 			cortex_ingester_tsdb_head_series_not_found_total 2081751
@@ -351,6 +358,12 @@ func TestTSDBMetricsWithRemoval(t *testing.T) {
 			# TYPE cortex_ingester_tsdb_head_active_appenders gauge
 			cortex_ingester_tsdb_head_active_appenders 1962640
 
+			# HELP cortex_ingester_tsdb_head_series Total number of series in the TSDB head block.
+			# TYPE cortex_ingester_tsdb_head_series gauge
+			# 20 * (12345 and 85787 and 999 respectively)
+			cortex_ingester_tsdb_head_series{user="user1"} 246900
+			cortex_ingester_tsdb_head_series{user="user2"} 1715740
+
 			# HELP cortex_ingester_tsdb_head_series_not_found_total Total number of TSDB requests for series that were not found.
 			# TYPE cortex_ingester_tsdb_head_series_not_found_total counter
 			cortex_ingester_tsdb_head_series_not_found_total 2081751
@@ -542,6 +555,12 @@ func populateTSDBMetrics(base float64) *prometheus.Registry {
 	})
 	checkpointCreationTotal.Add(19 * base)
 
+	series := promauto.With(r).NewGauge(prometheus.GaugeOpts{
+		Name: "prometheus_tsdb_head_series",
+		Help: "Total number of series in the head block.",
+	})
+	series.Set(20 * base)
+
 	activeAppenders := promauto.With(r).NewGauge(prometheus.GaugeOpts{
 		Name: "prometheus_tsdb_head_active_appenders",
 		Help: "Number of currently active appender transactions",