diff --git a/usr/local/bin/memory_usage_alert b/usr/local/bin/memory_usage_alert
index 40c0837..6ee3be0 100755
--- a/usr/local/bin/memory_usage_alert
+++ b/usr/local/bin/memory_usage_alert
@@ -27,7 +27,7 @@ set -e;
 HOSTNAME=$(hostname)
 SUBJECT="[memory $HOSTNAME] memory is low"
 MEMORY_USAGE_ALERT_MAIL_ADDRESS="";
-MEMORY_USAGE_ALERT_THRESHOLD=128;
+MEMORY_USAGE_ALERT_THRESHOLD=512;
 
 # check for config file
 source_config() {
@@ -52,7 +52,9 @@ source_config() {
 source_config "$1" "$HOME/.memory_usage_alert.conf"
 
 # DO NOT TOUCH BELOW
-free=$(free -mt | grep Total | awk '{print $4}')
+total=$(free -mt | grep Total | awk '{print $2}')
+used=$(free -mt | grep Total | awk '{print $3}')
+free=$(($total-$used))
 
 if [[ "$free" -le $MEMORY_USAGE_ALERT_THRESHOLD  ]]; then
         ps -eo pid,ppid,cmd,%mem,%cpu --sort=-%mem | head >/tmp/top_proccesses_consuming_memory.txt