diff --git a/at-tracker-sample-user-item-size b/at-tracker-sample-user-item-size
new file mode 100755
index 0000000..58cb9cf
--- /dev/null
+++ b/at-tracker-sample-user-item-size
@@ -0,0 +1,23 @@
+#!/bin/bash
+if [[ $# -ne 2 || "$1" == '--help' ]]
+then
+	echo "Usage: $0 PROJECT DURATION" >&2
+	echo 'Requests the PROJECT statistics from the AT tracker twice DURATION seconds apart, and calculates the average returned item size for each user within that window.' >&2
+	echo 'Output consists of lines of username SPACE SIZE, sorted by size ascending.' >&2
+	exit 1
+fi
+
+project="$1"
+declare -i duration="$2"
+
+{
+	curl -s "https://legacy-api.arpa.li/${project}/stats.json" | tr -d '\n'
+	echo
+
+	sleep ${duration}
+
+	curl -s "https://legacy-api.arpa.li/${project}/stats.json" | tr -d '\n'
+	echo
+} \
+| python3 -c 'import json,sys;o0=json.loads(sys.stdin.readline());o1=json.loads(sys.stdin.readline());[print(k,(o1["downloader_bytes"][k]-o0["downloader_bytes"][k])/(o1["downloader_count"][k]-o0["downloader_count"][k])) for k in o0["downloaders"] if o1["downloader_count"][k] != o0["downloader_count"][k]]' \
+| sort -k2,2n