diff --git a/pkg/cache/index/index.go b/pkg/cache/index/index.go
index f60877e10..c3ebb9e15 100644
--- a/pkg/cache/index/index.go
+++ b/pkg/cache/index/index.go
@@ -20,6 +20,7 @@ package index
 import (
 	"sort"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/tricksterproxy/trickster/pkg/cache"
@@ -191,10 +192,10 @@ func (idx *Index) UpdateObject(obj *Object) {
 	obj.LastWrite = obj.LastAccess
 
 	if o, ok := idx.Objects[key]; ok {
-		idx.CacheSize += o.Size - idx.Objects[key].Size
+		atomic.AddInt64(&idx.CacheSize, obj.Size-o.Size)
 	} else {
-		idx.CacheSize += obj.Size
-		idx.ObjectCount++
+		atomic.AddInt64(&idx.CacheSize, obj.Size)
+		atomic.AddInt64(&idx.ObjectCount, 1)
 	}
 
 	metrics.ObserveCacheSizeChange(idx.name, idx.cacheType, idx.CacheSize, idx.ObjectCount)
@@ -208,8 +209,8 @@ func (idx *Index) RemoveObject(key string) {
 	indexLock.Lock()
 	idx.lastWrite = time.Now()
 	if o, ok := idx.Objects[key]; ok {
-		idx.CacheSize -= o.Size
-		idx.ObjectCount--
+		atomic.AddInt64(&idx.CacheSize, -o.Size)
+		atomic.AddInt64(&idx.ObjectCount, -1)
 
 		metrics.ObserveCacheOperation(idx.name, idx.cacheType, "del", "none", float64(o.Size))
 
@@ -226,8 +227,8 @@ func (idx *Index) RemoveObjects(keys []string, noLock bool) {
 	}
 	for _, key := range keys {
 		if o, ok := idx.Objects[key]; ok {
-			idx.CacheSize -= o.Size
-			idx.ObjectCount--
+			atomic.AddInt64(&idx.CacheSize, -o.Size)
+			atomic.AddInt64(&idx.ObjectCount, -1)
 			metrics.ObserveCacheOperation(idx.name, idx.cacheType, "del", "none", float64(o.Size))
 			delete(idx.Objects, key)
 			metrics.ObserveCacheSizeChange(idx.name, idx.cacheType, idx.CacheSize, idx.ObjectCount)
diff --git a/pkg/proxy/origins/clickhouse/series.go b/pkg/proxy/origins/clickhouse/series.go
index 8b89fdc38..c17a98d6b 100644
--- a/pkg/proxy/origins/clickhouse/series.go
+++ b/pkg/proxy/origins/clickhouse/series.go
@@ -19,6 +19,7 @@ package clickhouse
 import (
 	"sort"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/tricksterproxy/trickster/pkg/sort/times"
@@ -462,52 +463,38 @@ func (re *ResultsEnvelope) ValueCount() int {
 
 // Size returns the approximate memory utilization in bytes of the timeseries
 func (re *ResultsEnvelope) Size() int {
-
-	var size int
 	wg := sync.WaitGroup{}
-
-	var a int
-	ma := sync.Mutex{}
+	c := uint64(24 + // .stepDuration
+		(25 * len(re.timestamps)) + // time.Time (24) + bool(1)
+		(24 * len(re.tslist)) + // time.Time (24)
+		(len(re.ExtentList) * 72) + // time.Time (24) * 3
+		2, // .isSorted + .isCounted
+	)
 	for i := range re.Meta {
 		wg.Add(1)
 		go func(j int) {
-			ma.Lock()
-			a += len(re.Meta[j].Name) + len(re.Meta[j].Type)
-			ma.Unlock()
+			atomic.AddUint64(&c, uint64(len(re.Meta[j].Name)+len(re.Meta[j].Type)))
 			wg.Done()
 		}(i)
 	}
-
-	var b int
-	mb := sync.Mutex{}
-	for k, v := range re.Data {
-		b += len(k)
-		wg.Add(1)
-		go func(d *DataSet) {
-			mb.Lock()
-			b += len(d.Points) * 16
-			mb.Unlock()
-			wg.Done()
-		}(v)
-	}
-
-	var c int
-	mc := sync.Mutex{}
 	for _, s := range re.SeriesOrder {
 		wg.Add(1)
 		go func(t string) {
-			mc.Lock()
-			c += len(t)
-			mc.Unlock()
+			atomic.AddUint64(&c, uint64(len(t)))
 			wg.Done()
 		}(s)
 	}
-
-	// ExtentList + StepDuration + Timestamps + Times + isCounted + isSorted
-	d := (len(re.ExtentList) * 24) + 8 + (len(re.timestamps) * 9) + (len(re.tslist) * 8) + 2
-
+	for k, v := range re.Data {
+		atomic.AddUint64(&c, uint64(len(k)))
+		wg.Add(1)
+		go func(d *DataSet) {
+			atomic.AddUint64(&c, uint64(len(d.Points)*32))
+			for mk := range d.Metric {
+				atomic.AddUint64(&c, uint64(len(mk)+8)) // + approx len of value (interface)
+			}
+			wg.Done()
+		}(v)
+	}
 	wg.Wait()
-	size = a + b + c + d
-	return size
-
+	return int(c)
 }
diff --git a/pkg/proxy/origins/clickhouse/series_test.go b/pkg/proxy/origins/clickhouse/series_test.go
index afeb70c1a..fc02d1968 100644
--- a/pkg/proxy/origins/clickhouse/series_test.go
+++ b/pkg/proxy/origins/clickhouse/series_test.go
@@ -1505,7 +1505,7 @@ func TestSize(t *testing.T) {
 		StepDuration: time.Duration(5) * time.Second,
 	}
 	i := r.Size()
-	const expected = 146
+	const expected = 370
 	if i != expected {
 		t.Errorf("expected %d got %d", expected, i)
 	}
diff --git a/pkg/proxy/origins/influxdb/series.go b/pkg/proxy/origins/influxdb/series.go
index 51e35d8b0..4fd185823 100644
--- a/pkg/proxy/origins/influxdb/series.go
+++ b/pkg/proxy/origins/influxdb/series.go
@@ -21,6 +21,7 @@ import (
 	"sort"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/tricksterproxy/trickster/pkg/sort/times"
@@ -459,28 +460,31 @@ func (se *SeriesEnvelope) Sort() {
 
 // Size returns the approximate memory utilization in bytes of the timeseries
 func (se *SeriesEnvelope) Size() int {
-	c := 8 + len(se.Err)
+	c := uint64(24 + // .stepDuration
+		len(se.Err) +
+		se.ExtentList.Size() + // time.Time (24) * 3
+		(25 * len(se.timestamps)) + // time.Time (24) + bool(1)
+		(24 * len(se.tslist)) + // time.Time (24)
+		2, // .isSorted + .isCounted
+	)
 	wg := sync.WaitGroup{}
-	mtx := sync.Mutex{}
-	for i := range se.Results {
-		for j := range se.Results[i].Series {
-
+	for i, res := range se.Results {
+		atomic.AddUint64(&c, uint64(8+len(res.Err))) // .StatementID
+		for j := range res.Series {
 			wg.Add(1)
 			go func(r models.Row) {
-				mtx.Lock()
-				c += len(r.Name)
+				atomic.AddUint64(&c, uint64(len(r.Name)+1)) // .Partial
 				for k, v := range r.Tags {
-					c += len(k) + len(v)
+					atomic.AddUint64(&c, uint64(len(k)+len(v)))
 				}
 				for _, v := range r.Columns {
-					c += len(v)
+					atomic.AddUint64(&c, uint64(len(v)))
 				}
-				c += 16 // approximate size of timestamp + value
-				mtx.Unlock()
+				atomic.AddUint64(&c, 32) // size of timestamp (24) + approximate value size (8)
 				wg.Done()
 			}(se.Results[i].Series[j])
 		}
 	}
 	wg.Wait()
-	return c
+	return int(c)
 }
diff --git a/pkg/proxy/origins/influxdb/series_test.go b/pkg/proxy/origins/influxdb/series_test.go
index eb174499e..13ba97039 100644
--- a/pkg/proxy/origins/influxdb/series_test.go
+++ b/pkg/proxy/origins/influxdb/series_test.go
@@ -1573,7 +1573,7 @@ func TestSize(t *testing.T) {
 	}
 
 	i := s.Size()
-	expected := 94
+	expected := 226
 
 	if i != expected {
 		t.Errorf("expected %d got %d", expected, i)
diff --git a/pkg/proxy/origins/irondb/model.go b/pkg/proxy/origins/irondb/model.go
index 1533f4407..8ad2fd1ca 100644
--- a/pkg/proxy/origins/irondb/model.go
+++ b/pkg/proxy/origins/irondb/model.go
@@ -359,9 +359,8 @@ func (c Client) UnmarshalInstantaneous(
 
 // Size returns the approximate memory utilization in bytes of the timeseries
 func (se *SeriesEnvelope) Size() int {
-
-	// TODO this implementation is a rough approximation to ensure we conform to the
-	// interface specification, it requires refinement in order to be in the ballpark
-	c := len(se.Data) * 24
+	c := len(se.Data)*36 + // time.Time (24) + Step (4) + Value (8)
+		(len(se.ExtentList) * 72) + // time.Time (24) * 3
+		24 // .StepDuration
 	return c
 }
diff --git a/pkg/proxy/origins/irondb/model_df4.go b/pkg/proxy/origins/irondb/model_df4.go
index 5bcca921a..19920b606 100644
--- a/pkg/proxy/origins/irondb/model_df4.go
+++ b/pkg/proxy/origins/irondb/model_df4.go
@@ -18,6 +18,7 @@ package irondb
 
 import (
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/tricksterproxy/trickster/pkg/timeseries"
@@ -325,22 +326,28 @@ func (se *DF4SeriesEnvelope) Sort() {
 
 // Size returns the approximate memory utilization in bytes of the timeseries
 func (se *DF4SeriesEnvelope) Size() int {
-
-	// TODO this implementation is a rough approximation to ensure we conform to the
-	// interface specification, it requires refinement in order to be in the ballpark
-
-	c := 24 + len(se.Ver) // accounts for head + ver
 	wg := sync.WaitGroup{}
-	mtx := sync.Mutex{}
+	c := uint64(len(se.Ver) +
+		24 + // .Head
+		24 + // .StepDuration
+		se.ExtentList.Size(),
+	)
+	for i := range se.Meta {
+		wg.Add(1)
+		go func(j int) {
+			for k := range se.Meta[i] {
+				atomic.AddUint64(&c, uint64(len(k)+8)) // + approximate Meta Value size (8)
+			}
+			wg.Done()
+		}(i)
+	}
 	for i := range se.Data {
 		wg.Add(1)
 		go func(s []interface{}) {
-			mtx.Lock()
-			c += (len(s) * 16)
-			mtx.Unlock()
+			atomic.AddUint64(&c, uint64(len(s)*16)) // + approximate data value size
 			wg.Done()
 		}(se.Data[i])
 	}
 	wg.Wait()
-	return c
+	return int(c)
 }
diff --git a/pkg/proxy/origins/irondb/model_df4_test.go b/pkg/proxy/origins/irondb/model_df4_test.go
index 68c85fa20..de413645f 100644
--- a/pkg/proxy/origins/irondb/model_df4_test.go
+++ b/pkg/proxy/origins/irondb/model_df4_test.go
@@ -366,22 +366,22 @@ func TestUnmarshalDF4Timeseries(t *testing.T) {
 
 	se := ts.(*DF4SeriesEnvelope)
 	if len(se.Data) != 2 {
-		t.Errorf(`Expected length: 2. got %d`, len(se.Data))
+		t.Errorf(`expected length: 2. got %d`, len(se.Data))
 		return
 	}
 
 	if se.Data[1][1] != 2.0 {
-		t.Errorf(`Expected value: 2.0. got %f`, se.Data[1][1])
+		t.Errorf(`expected value: 2.0. got %f`, se.Data[1][1])
 		return
 	}
 
 	if se.Head.Start != 300 {
-		t.Errorf(`Expected time start: 300. got %d`, se.Head.Start)
+		t.Errorf(`expected time start: 300. got %d`, se.Head.Start)
 		return
 	}
 
 	if se.Head.Period != 300 {
-		t.Errorf(`Expected time period: 300. got %d`, se.Head.Period)
+		t.Errorf(`expected time period: 300. got %d`, se.Head.Period)
 		return
 	}
 }
@@ -390,7 +390,7 @@ func TestSize(t *testing.T) {
 
 	client := &Client{}
 	s, _ := client.UnmarshalTimeseries([]byte(testDF4Response))
-	expected := 75
+	expected := 136
 
 	if s.Size() != expected {
 		t.Errorf("expected %d got %d", expected, s.Size())
diff --git a/pkg/proxy/origins/irondb/model_test.go b/pkg/proxy/origins/irondb/model_test.go
index a1d2dad6b..8a706c9bd 100644
--- a/pkg/proxy/origins/irondb/model_test.go
+++ b/pkg/proxy/origins/irondb/model_test.go
@@ -497,11 +497,11 @@ func TestTSSize(t *testing.T) {
 
 	s, _ := client.UnmarshalTimeseries(bytes)
 
-	expected := 48
+	expected := 96
 	size := s.Size()
 
 	if size != expected {
-		t.Errorf("got %d expected %d", size, expected)
+		t.Errorf("expected %d got %d", expected, size)
 	}
 
 }
diff --git a/pkg/proxy/origins/prometheus/matrix.go b/pkg/proxy/origins/prometheus/matrix.go
index 03ed4278a..2351dd1d8 100644
--- a/pkg/proxy/origins/prometheus/matrix.go
+++ b/pkg/proxy/origins/prometheus/matrix.go
@@ -19,6 +19,7 @@ package prometheus
 import (
 	"sort"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/tricksterproxy/trickster/pkg/sort/times"
@@ -401,19 +402,21 @@ func (me *MatrixEnvelope) ValueCount() int {
 
 // Size returns the approximate memory utilization in bytes of the timeseries
 func (me *MatrixEnvelope) Size() int {
-
-	c := 0
 	wg := sync.WaitGroup{}
-	mtx := sync.Mutex{}
+	c := uint64(len(me.Status) +
+		me.ExtentList.Size() +
+		24 + // me.StepDuration
+		(25 * len(me.timestamps)) +
+		(24 * len(me.tslist)) +
+		2 + // isSorted + isCounted
+		len(me.Data.ResultType))
 	for i := range me.Data.Result {
 		wg.Add(1)
 		go func(s *model.SampleStream) {
-			mtx.Lock()
-			c += (len(s.Values) * 16) + len(s.Metric.String())
-			mtx.Unlock()
+			atomic.AddUint64(&c, uint64((len(s.Values)*32)+len(s.Metric.String())))
 			wg.Done()
 		}(me.Data.Result[i])
 	}
 	wg.Wait()
-	return c
+	return int(c)
 }
diff --git a/pkg/proxy/origins/prometheus/matrix_test.go b/pkg/proxy/origins/prometheus/matrix_test.go
index 735ae4a9e..0ad41bb2e 100644
--- a/pkg/proxy/origins/prometheus/matrix_test.go
+++ b/pkg/proxy/origins/prometheus/matrix_test.go
@@ -1701,7 +1701,7 @@ func TestSize(t *testing.T) {
 		StepDuration: time.Duration(5) * time.Second,
 	}
 	i := m.Size()
-	expected := 17
+	expected := 144
 
 	if i != expected {
 		t.Errorf("expected %d got %d", expected, i)
diff --git a/pkg/timeseries/extent_list.go b/pkg/timeseries/extent_list.go
index 6f58d7c40..203a2cade 100644
--- a/pkg/timeseries/extent_list.go
+++ b/pkg/timeseries/extent_list.go
@@ -164,6 +164,11 @@ func (el ExtentList) Clone() ExtentList {
 	return c
 }
 
+// Size returns the approximate memory utilization in bytes of the timeseries
+func (el ExtentList) Size() int {
+	return len(el) * 72
+}
+
 // ExtentListLRU is a type of []Extent used for sorting the slice by LRU
 type ExtentListLRU []Extent