diff --git a/src/AutoConnect.cpp b/src/AutoConnect.cpp
index a078a1c..936cc87 100644
--- a/src/AutoConnect.cpp
+++ b/src/AutoConnect.cpp
@@ -2,8 +2,8 @@
  *  AutoConnect class implementation.
  *  @file   AutoConnect.cpp
  *  @author hieromon@gmail.com
- *  @version    1.1.5
- *  @date   2020-04-15
+ *  @version    1.2.0
+ *  @date   2020-04-22
  *  @copyright  MIT license.
  */
 
@@ -746,6 +746,15 @@ bool AutoConnect::_loadAvailCredential(const char* ssid, const AC_PRINCIPLE_t pr
   return false;
 }
 
+/**
+ *  Get current AutoConnectCredential size
+ *  @return  Size of the AutoConnectCredential
+ */
+uint16_t AutoConnect::getCredentialSize(void) {
+  AutoConnectCredential credentials(_apConfig.boundaryOffset);
+  return credentials.dataSize();
+}
+
 /**
  *  Disconnect from the AP and stop the AutoConnect portal.
  *  Stops DNS server and flush tcp sending.
diff --git a/src/AutoConnect.h b/src/AutoConnect.h
index a483087..671802a 100644
--- a/src/AutoConnect.h
+++ b/src/AutoConnect.h
@@ -2,8 +2,8 @@
  *	Declaration of AutoConnect class and accompanying AutoConnectConfig class.
  *	@file	AutoConnect.h
  *	@author	hieromon@gmail.com
- *	@version	1.1.5
- *	@date	2020-04-01
+ *	@version	1.2.0
+ *	@date	2020-04-22
  *	@copyright	MIT license.
  */
 
@@ -252,6 +252,7 @@ class AutoConnect {
   String where(void) const { return _auxUri; }
   inline void enableMenu(const uint16_t items) { _apConfig.menuItems |= items; }
   inline void disableMenu(const uint16_t items) { _apConfig.menuItems &= (0xffff ^ items); }
+  uint16_t getCredentialSize(void);
 
   /** For AutoConnectAux described in JSON */
 #ifdef AUTOCONNECT_USE_JSON
diff --git a/src/AutoConnectCredential.h b/src/AutoConnectCredential.h
index 1a22fc9..3e33de0 100644
--- a/src/AutoConnectCredential.h
+++ b/src/AutoConnectCredential.h
@@ -2,8 +2,8 @@
  *  Declaration of AutoConnectCredential class.
  *  @file AutoConnectCredential.h
  *  @author hieromon@gmail.com
- *  @version  1.1.0
- *  @date 2019-10-07
+ *  @version  1.2.0
+ *  @date 2020-04-22
  *  @copyright  MIT license.
  */
 
@@ -78,7 +78,8 @@ class AutoConnectCredentialBase {
  public:
   explicit AutoConnectCredentialBase() : _entries(0), _containSize(0) {}
   virtual ~AutoConnectCredentialBase() {}
-  virtual uint8_t entries(void) { return _entries; }
+  virtual uint8_t entries(void) const { return _entries; }
+  virtual uint16_t dataSize(void) const { return sizeof(AC_IDENTIFIER) - 1 + sizeof(uint8_t) + sizeof(uint16_t) + _containSize; }
   virtual bool    del(const char* ssid) = 0;
   virtual int8_t  load(const char* ssid, station_config_t* config) = 0;
   virtual bool    load(int8_t entry, station_config_t* config) = 0;