diff --git a/webui/model/health/health.php b/webui/model/health/health.php
index 55037c2..d6316cb 100644
--- a/webui/model/health/health.php
+++ b/webui/model/health/health.php
@@ -70,8 +70,8 @@
          if(isset($a[0]) && $a[0]) { $_m[$a[0]] = $a[1]; }
       }
 
-      $mem_percentage = isset($_m['MemTotal:']) ? sprintf("%.2f", 100*($_m['MemTotal:'] - $_m['MemFree:'] - $_m['Cached:']) / $_m['MemTotal:']) : "0";
-      $swap_percentage = isset($_m['SwapTotal:']) ? sprintf("%.2f", 100*($_m['SwapTotal:'] - $_m['SwapFree:']) / $_m['SwapTotal:']) : "0";
+      $mem_percentage = isset($_m['MemTotal:']) && $_m['MemTotal:'] > 0 ? sprintf("%.2f", 100*($_m['MemTotal:'] - $_m['MemFree:'] - $_m['Cached:']) / $_m['MemTotal:']) : "0";
+      $swap_percentage = isset($_m['SwapTotal:']) && $_m['SwapTotal:'] > 0 ? sprintf("%.2f", 100*($_m['SwapTotal:'] - $_m['SwapFree:']) / $_m['SwapTotal:']) : "0";
 
       return array(sprintf("%.0f", @$_m['MemTotal:'] / 1000), $mem_percentage, sprintf("%.0f", @$_m['SwapTotal:'] / 1000), $swap_percentage);
    }