diff --git a/reth/check_reth_datadir.sh b/reth/check_reth_datadir.sh
new file mode 100644
index 00000000..38541816
--- /dev/null
+++ b/reth/check_reth_datadir.sh
@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Small helper to inspect disk usage of a Base Reth data directory.
+#
+# This can be used before upgrades or when planning storage for a new node.
+#
+# Usage:
+#   BASE_RETH_DATADIR=/data/reth ./reth/check_reth_datadir.sh
+
+DATADIR="${BASE_RETH_DATADIR:-/data/reth}"
+
+if [ ! -d "${DATADIR}" ]; then
+  echo "[reth] Data directory does not exist:"
+  echo "  ${DATADIR}"
+  echo
+  echo "Set BASE_RETH_DATADIR to the correct path before running this script."
+  exit 1
+fi
+
+echo "== Base Reth datadir disk usage =="
+echo "Path: ${DATADIR}"
+echo
+
+if command -v du >/dev/null 2>&1; then
+  du -sh "${DATADIR}"
+  echo
+  echo "Top-level subdirectories:"
+  du -sh "${DATADIR}"/* 2>/dev/null | sort -h
+else
+  echo "The 'du' command is not available on this system."
+fi
+
+echo
+echo "Tip: keep this directory on a fast local NVMe SSD for best performance."