diff --git a/health-check.sh b/health-check.sh
index 411ef4c..779549c 100755
--- a/health-check.sh
+++ b/health-check.sh
@@ -62,16 +62,16 @@ check_disk() {
             ok "Disk usage at ${pct}% on $mount"
         fi
     done < <(df -h | awk 'NR>1' | grep -v ' /dev' | grep -v ' /sys' | grep -v ' /proc' | grep -v ' /run' | grep -v ' /snap' | grep -v 'overlay2' | grep -v 'docker')
-    local used_kb total_kb total_pct
-    used_kb=$(df --block-size=1K / | awk 'NR==2 {print $3}')
-    total_kb=$(df --block-size=1K / | awk 'NR==2 {print $2}')
-    total_pct=$(( used_kb * 100 / total_kb ))
+    local used_human total_human total_pct
+    used_human=$(df -h / | awk 'NR==2 {print $3}')
+    total_human=$(df -h / | awk 'NR==2 {print $2}')
+    total_pct=$(df / | awk 'NR==2 {print $5}' | tr -d '%')
     if [ "$total_pct" -ge 90 ]; then
-        fail "Total disk usage at ${total_pct}% (root filesystem) — critically low"
+        fail "Total disk usage ${used_human} of ${total_human} — critically low"
     elif [ "$total_pct" -ge 80 ]; then
-        warn "Total disk usage at ${total_pct}% (root filesystem)"
+        warn "Total disk usage ${used_human} of ${total_human}"
     else
-        ok "Total disk usage at ${total_pct}% (root filesystem)"
+        ok "Total disk usage ${used_human} of ${total_human}"
     fi
 }