diff --git a/proxy/proxy.go b/proxy/proxy.go
index a024a2cc12..e711718085 100644
--- a/proxy/proxy.go
+++ b/proxy/proxy.go
@@ -521,6 +521,16 @@ func cloneHeaderExcluding(h http.Header, excludeList map[string]bool) http.Heade
 	return hh
 }
 
+func sizeOfHeader(h http.Header) (size int) {
+	for k, vv := range h {
+		size += len(k)
+		for _, v := range vv {
+			size += len(v)
+		}
+	}
+	return
+}
+
 type flusher struct {
 	w flushedResponseWriter
 }
@@ -1382,6 +1392,7 @@ func (p *Proxy) serveResponse(ctx *context) {
 	p.tracing.logStreamEvent(ctx.proxySpan, StreamHeadersEvent, EndEvent)
 
 	n, err := copyStream(ctx.responseWriter, ctx.response.Body)
+	p.tracing.setTag(ctx.proxySpan, HTTPResponseBodyCeil, ceilPow2(n))
 	p.tracing.logStreamEvent(ctx.proxySpan, StreamBodyEvent, strconv.FormatInt(n, 10))
 	if err != nil {
 		p.metrics.IncErrorsStreaming(ctx.route.Id)
@@ -1660,7 +1671,9 @@ func (p *Proxy) setCommonSpanInfo(u *url.URL, r *http.Request, s ot.Span) {
 		setTag(s, HTTPMethodTag, r.Method).
 		setTag(s, HostnameTag, p.hostname).
 		setTag(s, HTTPPathTag, u.Path).
-		setTag(s, HTTPHostTag, r.Host)
+		setTag(s, HTTPHostTag, r.Host).
+		setTag(s, HTTPRequestHeaderCeil, ceilPow2(int64(sizeOfHeader(r.Header))))
+
 	if val := r.Header.Get("X-Flow-Id"); val != "" {
 		p.tracing.setTag(s, FlowIDTag, val)
 	}
diff --git a/proxy/tracing.go b/proxy/tracing.go
index 66b481c8f3..efbe62ecbf 100644
--- a/proxy/tracing.go
+++ b/proxy/tracing.go
@@ -1,6 +1,8 @@
 package proxy
 
 import (
+	"math"
+
 	ot "github.com/opentracing/opentracing-go"
 
 	"github.com/zalando/skipper/tracing"
@@ -19,6 +21,8 @@ const (
 	HTTPPathTag           = "http.path"
 	HTTPUrlTag            = "http.url"
 	HTTPStatusCodeTag     = "http.status_code"
+	HTTPResponseBodyCeil  = "http.response.body_ceil"
+	HTTPRequestHeaderCeil = "http.request.header_ceil"
 	SkipperRouteIDTag     = "skipper.route_id"
 	SpanKindTag           = "span.kind"
 
@@ -135,3 +139,7 @@ func (t *filterTracing) logEnd(filterName string) {
 		t.span.LogKV(filterName, EndEvent)
 	}
 }
+
+func ceilPow2(n int64) int64 {
+	return int64(math.Pow(2, math.Ceil(math.Log2(float64(n)))))
+}
diff --git a/proxy/tracing_test.go b/proxy/tracing_test.go
index 92d3ad3ff0..68d0c07c9d 100644
--- a/proxy/tracing_test.go
+++ b/proxy/tracing_test.go
@@ -76,8 +76,10 @@ func TestTracingIngressSpan(t *testing.T) {
 	verifyTag(t, span, HostnameTag, "ingress.tracing.test")
 	verifyTag(t, span, HTTPPathTag, "/hello")
 	verifyTag(t, span, HTTPHostTag, ps.Listener.Addr().String())
+	verifyTag(t, span, HTTPRequestHeaderCeil, int64(128))
 	verifyTag(t, span, FlowIDTag, "test-flow-id")
 	verifyTag(t, span, HTTPStatusCodeTag, uint16(200))
+	verifyNoTag(t, span, HTTPResponseBodyCeil)
 	verifyHasTag(t, span, HTTPRemoteIPTag)
 }
 
@@ -131,8 +133,10 @@ func TestTracingIngressSpanShunt(t *testing.T) {
 	verifyTag(t, span, HostnameTag, "ingress-shunt.tracing.test")
 	verifyTag(t, span, HTTPPathTag, "/hello")
 	verifyTag(t, span, HTTPHostTag, ps.Listener.Addr().String())
+	verifyTag(t, span, HTTPRequestHeaderCeil, int64(128))
 	verifyTag(t, span, FlowIDTag, "test-flow-id")
 	verifyTag(t, span, HTTPStatusCodeTag, uint16(205))
+	verifyNoTag(t, span, HTTPResponseBodyCeil)
 	verifyHasTag(t, span, HTTPRemoteIPTag)
 }
 
@@ -204,7 +208,9 @@ func TestTracingIngressSpanLoopback(t *testing.T) {
 		verifyTag(t, span, HostnameTag, "ingress-loop.tracing.test")
 		verifyTag(t, span, HTTPPathTag, paths[rid])
 		verifyTag(t, span, HTTPHostTag, ps.Listener.Addr().String())
+		verifyTag(t, span, HTTPRequestHeaderCeil, int64(128))
 		verifyTag(t, span, FlowIDTag, "test-flow-id")
+		verifyNoTag(t, span, HTTPResponseBodyCeil)
 	}
 }
 
@@ -286,7 +292,8 @@ func TestTracingProxySpan(t *testing.T) {
 		if err != nil {
 			t.Error(err)
 		}
-		w.WriteHeader(http.StatusNoContent)
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("OK\n"))
 	}))
 	defer s.Close()
 
@@ -310,10 +317,11 @@ func TestTracingProxySpan(t *testing.T) {
 	}
 	req.Header.Set("X-Flow-Id", "test-flow-id")
 
-	_, err = http.DefaultClient.Do(req)
+	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		t.Fatal(err)
 	}
+	resp.Body.Close()
 
 	span := tracer.FindSpan("proxy")
 	if span == nil {
@@ -330,8 +338,10 @@ func TestTracingProxySpan(t *testing.T) {
 	verifyTag(t, span, HostnameTag, "proxy.tracing.test")
 	verifyTag(t, span, HTTPPathTag, "/bye")
 	verifyTag(t, span, HTTPHostTag, backendAddr)
+	verifyTag(t, span, HTTPRequestHeaderCeil, int64(128))
 	verifyTag(t, span, FlowIDTag, "test-flow-id")
-	verifyTag(t, span, HTTPStatusCodeTag, uint16(204))
+	verifyTag(t, span, HTTPStatusCodeTag, uint16(200))
+	verifyTag(t, span, HTTPResponseBodyCeil, int64(4))
 	verifyNoTag(t, span, HTTPRemoteIPTag)
 }
 
@@ -636,3 +646,21 @@ func verifyHasTag(t *testing.T, span *tracingtest.MockSpan, name string) {
 		t.Errorf("expected '%s' tag", name)
 	}
 }
+
+func TestCeilPow2(t *testing.T) {
+	assert.Equal(t, int64(0), ceilPow2(0))
+	assert.Equal(t, int64(1), ceilPow2(1))
+	assert.Equal(t, int64(2), ceilPow2(2))
+	assert.Equal(t, int64(4), ceilPow2(3))
+	assert.Equal(t, int64(4), ceilPow2(4))
+	assert.Equal(t, int64(8), ceilPow2(5))
+	assert.Equal(t, int64(8), ceilPow2(6))
+	assert.Equal(t, int64(8), ceilPow2(7))
+	assert.Equal(t, int64(8), ceilPow2(8))
+	assert.Equal(t, int64(16), ceilPow2(9))
+
+	assert.Equal(t, int64(16384), ceilPow2(10_000))
+	assert.Equal(t, int64(16384), ceilPow2(16_000))
+	assert.Equal(t, int64(32768), ceilPow2(16_385))
+	assert.Equal(t, int64(32768), ceilPow2(20_000))
+}