Index: /trunk/FACT++/src/Converter.cc
===================================================================
--- /trunk/FACT++/src/Converter.cc	(revision 11701)
+++ /trunk/FACT++/src/Converter.cc	(revision 11702)
@@ -645,5 +645,5 @@
         {
             ostringstream err;
-            err << "Format description [fmt=" << fFormat << "] exceeds available data size (" << size << ")";
+            err << "Format description [fmt=" << fFormat << "|size=" << GetSize() << "] exceeds available data size (" << size << ")";
             throw runtime_error(err.str());
         }
@@ -685,5 +685,5 @@
     {
         ostringstream err;
-        err << "Data block size (" << size << ") doesn't fit format description [fmt=" << fFormat << "]";
+        err << "Data block size (" << size << ") doesn't fit format description [fmt=" << fFormat << "|size=" << GetSize() <<"]";
         throw runtime_error(err.str());
     }
@@ -916,5 +916,5 @@
    {
        ostringstream err;
-       err << "ToFits - Data block size (" << size << ") doesn't fit format description [fmt=" << fFormat << "]";
+       err << "ToFits - Data block size (" << size << ") doesn't fit format description [fmt=" << fFormat << "|size=" << GetSize() << "]";
        throw runtime_error(err.str());
    }
Index: /trunk/FACT++/src/Converter.h
===================================================================
--- /trunk/FACT++/src/Converter.h	(revision 11701)
+++ /trunk/FACT++/src/Converter.h	(revision 11702)
@@ -85,4 +85,5 @@
 
     const FormatList &GetList() const { return fList; }
+    size_t GetSize() const { return fList.size()==0 ? 0 : fList.back().second.second; }
 
     static FormatList Compile(std::ostream &out, const std::string &fmt, bool strict=false);