diff --git a/build.gradle.kts b/build.gradle.kts
index cb35894..7521b7b 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -46,6 +46,8 @@ dependencies {
     testImplementation(Junit5.kotlinRunner)
     testImplementation(Json.library)
     testRuntimeOnly(Junit5.engine)
+
+    implementation(Prometheus.common)
 }
 
 val sourcesJar by tasks.registering(Jar::class) {
diff --git a/src/main/kotlin/no/nav/dagpenger/events/Metrics.kt b/src/main/kotlin/no/nav/dagpenger/events/Metrics.kt
new file mode 100644
index 0000000..0cf0d22
--- /dev/null
+++ b/src/main/kotlin/no/nav/dagpenger/events/Metrics.kt
@@ -0,0 +1,7 @@
+package no.nav.dagpenger.events
+
+import io.prometheus.client.Summary
+
+val packetPayloadByteSize = Summary.build()
+    .name("payload_size_bytes")
+    .help("Packet payload size in bytes.").register()
\ No newline at end of file
diff --git a/src/main/kotlin/no/nav/dagpenger/events/Packet.kt b/src/main/kotlin/no/nav/dagpenger/events/Packet.kt
index 4044c2d..e444b6c 100644
--- a/src/main/kotlin/no/nav/dagpenger/events/Packet.kt
+++ b/src/main/kotlin/no/nav/dagpenger/events/Packet.kt
@@ -49,9 +49,12 @@ class Packet constructor(jsonString: String = "{}") {
         System.getenv("NAIS_APP_NAME")?.let {
             val breadcrumb = Breadcrumb(
                 it,
-                LocalDateTime.now())
+                LocalDateTime.now()
+            )
             breadcrumbs.add(breadcrumb)
         }
+
+        packetPayloadByteSize.observe(jsonString.toByteArray().size.toDouble())
     }
 
     private fun getValue(key: String): Any? = json[key]
diff --git a/src/test/kotlin/no/nav/dagpenger/events/PacketTest.kt b/src/test/kotlin/no/nav/dagpenger/events/PacketTest.kt
index 9cfa34c..4b91797 100644
--- a/src/test/kotlin/no/nav/dagpenger/events/PacketTest.kt
+++ b/src/test/kotlin/no/nav/dagpenger/events/PacketTest.kt
@@ -3,7 +3,6 @@ package no.nav.dagpenger.events
 import com.squareup.moshi.JsonEncodingException
 import io.kotlintest.shouldBe
 import org.json.JSONObject
-
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Assertions.assertFalse
 import org.junit.jupiter.api.Test
@@ -391,6 +390,13 @@ class PacketTest {
         Packet(packet.toJson()!!).getCorrelationId() shouldBe packet.getCorrelationId()
     }
 
+    @Test
+    fun `Initialization of Packet should increment summary count`() {
+        packetPayloadByteSize.clear()
+        val packet = Packet()
+        packetPayloadByteSize.get().count shouldBe 1.0
+    }
+
     data class ClassA(
         val id: String,
         val list: List<ClassB>