diff --git a/cache.go b/cache.go
index 29094cc..80fa165 100644
--- a/cache.go
+++ b/cache.go
@@ -1,7 +1,6 @@
 package ttlcache
 
 import (
-	"errors"
 	"sync"
 	"time"
 )
@@ -32,19 +31,27 @@
 	isShutDown             bool
 	loaderFunction         LoaderFunction
 	sizeLimit              int
-}
-
-var (
+	metrics                Metrics
+}
+
+const (
 	// ErrClosed is raised when operating on a cache where Close() has already been called.
-	ErrClosed = errors.New("cache already closed")
+	ErrClosed = constError("cache already closed")
 	// ErrNotFound indicates that the requested key is not present in the cache
-	ErrNotFound = errors.New("key not found")
+	ErrNotFound = constError("key not found")
 )
+
+type constError string
+
+func (err constError) Error() string {
+	return string(err)
+}
 
 func (cache *Cache) getItem(key string) (*item, bool, bool) {
 	item, exists := cache.items[key]
 	if !exists || item.expired() {
 		return nil, false, false
+	} else {
 	}
 
 	if item.ttl >= 0 && (item.ttl > 0 || cache.ttl > 0) {
@@ -120,6 +127,7 @@
 }
 
 func (cache *Cache) removeItem(item *item) {
+	cache.metrics.Evicted++
 	if cache.expireCallback != nil {
 		go cache.expireCallback(item.key, item.data)
 	}
@@ -207,6 +215,7 @@
 		item = newItem(key, data, ttl)
 		cache.items[key] = item
 	}
+	cache.metrics.Inserted++
 
 	if item.ttl >= 0 && (item.ttl > 0 || cache.ttl > 0) {
 		if cache.ttl > 0 && item.ttl == 0 {
@@ -237,15 +246,19 @@
 		cache.mutex.Unlock()
 		return nil, ErrClosed
 	}
+
+	cache.metrics.Hits++
 	item, exists, triggerExpirationNotification := cache.getItem(key)
 
 	var dataToReturn interface{}
 	if exists {
+		cache.metrics.Retrievals++
 		dataToReturn = item.data
 	}
 
 	var err error
 	if !exists {
+		cache.metrics.Misses++
 		err = ErrNotFound
 	}
 	if cache.loaderFunction == nil || exists {
@@ -381,6 +394,7 @@
 	if cache.isShutDown {
 		return ErrClosed
 	}
+	cache.metrics.Evicted += int64(len(cache.items))
 	cache.items = make(map[string]*item)
 	cache.priorityQueue = newPriorityQueue()
 	return nil
@@ -408,9 +422,17 @@
 		isShutDown:             false,
 		loaderFunction:         nil,
 		sizeLimit:              0,
+		metrics:                Metrics{},
 	}
 	go cache.startExpirationProcessing()
 	return cache
+}
+
+// GetMetrics exposes the metrics of the cache. This is a snapshot copy of the metrics.
+func (cache *Cache) GetMetrics() Metrics {
+	cache.mutex.Lock()
+	defer cache.mutex.Unlock()
+	return cache.metrics
 }
 
 func min(duration time.Duration, second time.Duration) time.Duration {
diff --git a/cache_test.go b/cache_test.go
index a062cfc..ca9e11f 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -1,13 +1,14 @@
 package ttlcache_test
 
 import (
-	"go.uber.org/goleak"
 	"math/rand"
 	"strconv"
 	"sync/atomic"
 	"testing"
 	"time"
 
+	"go.uber.org/goleak"
+
 	"fmt"
 	"sync"
 
@@ -17,6 +18,38 @@
 
 func TestMain(m *testing.M) {
 	goleak.VerifyTestMain(m)
+}
+
+// Issue #37: Cache metrics
+func TestCache_TestMetrics(t *testing.T) {
+	t.Parallel()
+	cache := NewCache()
+	defer cache.Close()
+
+	cache.SetTTL(time.Second)
+	cache.Set("myKey", "myData")
+	cache.SetWithTTL("myKey2", "myData", time.Second)
+
+	cache.Get("myKey")
+	cache.Get("myMiss")
+
+	metrics := cache.GetMetrics()
+	assert.Equal(t, int64(2), metrics.Inserted)
+	assert.Equal(t, int64(1), metrics.Misses)
+	assert.Equal(t, int64(2), metrics.Hits)
+	assert.Equal(t, int64(1), metrics.Retrievals)
+	cache.Purge()
+	metrics = cache.GetMetrics()
+	assert.Equal(t, int64(2), metrics.Evicted)
+
+	cache.SetWithTTL("3", "3", time.Nanosecond)
+	cache.SetWithTTL("4", "4", time.Nanosecond)
+	cache.Count()
+	time.Sleep(time.Millisecond * 10)
+
+	metrics = cache.GetMetrics()
+	assert.Equal(t, int64(4), metrics.Evicted)
+
 }
 
 // Issue #31: Test that a single fetch is executed with the loader function
diff --git a/go.mod b/go.mod
index 6e17f31..b5cee44 100644
--- a/go.mod
+++ b/go.mod
@@ -1,11 +1,11 @@
 module github.com/ReneKroon/ttlcache/v2
 
-go 1.14
+go 1.15
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/stretchr/testify v1.6.1
+	github.com/stretchr/testify v1.7.0
 	go.uber.org/goleak v1.1.10
-	golang.org/x/lint v0.0.0-20200302205851-738671d3881b // indirect
-	golang.org/x/tools v0.0.0-20200804011535-6c149bb5ef0d // indirect
+	golang.org/x/lint v0.0.0-20201208152925-83fdc39ff7b5 // indirect
+	golang.org/x/tools v0.0.0-20210112230658-8b4aab62c064 // indirect
 )
diff --git a/go.sum b/go.sum
index fe55b5a..d6ffb20 100644
--- a/go.sum
+++ b/go.sum
@@ -1,12 +1,17 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
@@ -14,7 +19,10 @@
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.uber.org/goleak v1.1.10 h1:z+mqJhf6ss6BSfSM671tgKyZBFPTTJM+HLxnhPC3wu0=
 go.uber.org/goleak v1.1.10/go.mod h1:8a7PlsEVH3e/a/GLqe5IIrQx6GzcnRmZEufDUTk4A7A=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
@@ -24,19 +32,28 @@
 golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/lint v0.0.0-20200302205851-738671d3881b h1:Wh+f8QHJXR411sJR8/vRBTZ7YapZaRvUcLFFJhusH0k=
 golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
+golang.org/x/lint v0.0.0-20201208152925-83fdc39ff7b5 h1:2M3HP5CCK1Si9FQhwnzYhXdG6DXeebvUHFpre8QvbyI=
+golang.org/x/lint v0.0.0-20201208152925-83fdc39ff7b5/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
 golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
 golang.org/x/mod v0.3.0 h1:RM4zey1++hCTbCVQfnWeKs9/IEsaBLA8vTkd0WVtmH4=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.4.0 h1:8pl+sMODzuvGJkmj2W4kZihvVb5mKm8pB/X44PIQHv8=
+golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200625001655-4c5254603344/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20191108193012-7d206e10da11 h1:Yq9t9jnGoR+dBuitxdo9l6Q7xh/zOyNnYUtDKaQ3x0E=
 golang.org/x/tools v0.0.0-20191108193012-7d206e10da11/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
@@ -44,13 +61,21 @@
 golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
 golang.org/x/tools v0.0.0-20200804011535-6c149bb5ef0d h1:szSOL78iTCl0LF1AMjhSWJj8tIM0KixlUUnBtYXsmd8=
 golang.org/x/tools v0.0.0-20200804011535-6c149bb5ef0d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
+golang.org/x/tools v0.0.0-20210112230658-8b4aab62c064 h1:BmCFkEH4nJrYcAc2L08yX5RhYGD4j58PTMkEUDkpz2I=
+golang.org/x/tools v0.0.0-20210112230658-8b4aab62c064/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/metrics.go b/metrics.go
new file mode 100644
index 0000000..5f672b1
--- /dev/null
+++ b/metrics.go
@@ -0,0 +1,15 @@
+package ttlcache
+
+// Metrics contains common cache metrics so you can calculate hit and miss rates
+type Metrics struct {
+	// succesful inserts
+	Inserted int64
+	// retrieval attempts
+	Retrievals int64
+	// all get calls that were in the cache (excludes loader invocations)
+	Hits int64
+	// entries not in cache (includes loader invocations)
+	Misses int64
+	// items removed from the cache in any way
+	Evicted int64
+}