diff --git a/bin/st-mem b/bin/st-mem
index 57b1a0a..d8d4e17 100755
--- a/bin/st-mem
+++ b/bin/st-mem
@@ -1,3 +1,18 @@
 #!/bin/sh
-MEMORY_USED=$(free -h | awk 'NR==2 {print $3}')
+#MEMORY_USED=$(free -h | awk 'NR==2 {print $3}')
+
+# freebsd (and maybe better for linux too)
+PAGES_WIRED=$(sysctl vm.stats.vm.v_wire_count | awk '{print $2}')
+PAGES_ACTIVE=$(sysctl vm.stats.vm.v_active_count | awk '{print $2}')
+PAGES_DIRTY=$(sysctl vm.stats.vm.v_laundry_count | awk '{print $2}')
+TOTAL_PAGES=$(echo "scale=0; $PAGES_WIRED+$PAGES_ACTIVE+$PAGES_DIRTY" | bc)
+
+BYTES_USED=$(echo "scale=0; $TOTAL_PAGES*4096" | bc)
+
+if [ $BYTES_USED -ge 1073741824 ]; then
+  MEMORY_USED="$(echo "scale=1; $BYTES_USED/1024^3" | bc) GiB"
+else
+  MEMORY_USED="$(echo "scale=1; $BYTES_USED/1024^2" | bc) MiB"
+fi
+
 echo $MEMORY_USED