diff --git a/clients/client-linux.py b/clients/client-linux.py
index bf40803..cb2b6c7 100755
--- a/clients/client-linux.py
+++ b/clients/client-linux.py
@@ -40,11 +40,11 @@ def get_memory():
             continue
         key, value = match.groups(['key', 'value'])
         result[key] = int(value)
-
+    # mem used refer to: htop software
+    # https://stackoverflow.com/questions/41224738/how-to-calculate-system-memory-usage-from-proc-meminfo-like-htop
     MemTotal = float(result['MemTotal'])
-    MemFree = float(result['MemFree'])
-    Cached = float(result['Cached'])
-    MemUsed = MemTotal - (Cached + MemFree)
+    MemExactCache = float(result['Cached'])+float(result['SReclaimable'])-float(result['Shmem'])
+    MemUsed = MemTotal-float(result['MemFree'])-(float(result['Buffers'])+MemExactCache)
     SwapTotal = float(result['SwapTotal'])
     SwapFree = float(result['SwapFree'])
     return int(MemTotal), int(MemUsed), int(SwapTotal), int(SwapFree)
diff --git a/clients/client-psutil.py b/clients/client-psutil.py
index 6a076c0..62785c8 100755
--- a/clients/client-psutil.py
+++ b/clients/client-psutil.py
@@ -28,11 +28,7 @@ def get_uptime():
 
 def get_memory():
     Mem = psutil.virtual_memory()
-    try:
-        MemUsed = Mem.total - (Mem.cached + Mem.free)
-    except:
-        MemUsed = Mem.total - Mem.free
-    return int(Mem.total/1024.0), int(MemUsed/1024.0)
+    return int(Mem.total / 1024.0), int(Mem.used / 1024.0)
 
 def get_swap():
     Mem = psutil.swap_memory()