diff --git a/acclimatise/cli_types.py b/acclimatise/cli_types.py
index 4df8ed8..1a7338b 100644
--- a/acclimatise/cli_types.py
+++ b/acclimatise/cli_types.py
@@ -13,6 +13,11 @@ class CliType:
     A data type used in the command-line
     """
 
+    default: Optional[typing.Any] = None
+    """
+    A default value, None if unknown
+    """
+
     @property
     def representable(self) -> set:
         """
@@ -31,6 +36,11 @@ class CliEnum(CliType):
     One of a list of possible options
     """
 
+    default: Optional[Enum] = None
+    """
+    A default value, None if unknown
+    """
+
     enum: Enum
     """
     The possible options as a Python Enum
@@ -43,7 +53,10 @@ class CliFloat(CliType):
     Takes a floating-point value
     """
 
-    pass
+    default: Optional[float] = None
+    """
+    A default value, None if unknown
+    """
 
 
 @dataclass(unsafe_hash=True)
@@ -52,6 +65,11 @@ class CliInteger(CliType):
     Takes an integer value
     """
 
+    default: Optional[int] = None
+    """
+    A default value, None if unknown
+    """
+
     _representable = {CliFloat}
 
 
@@ -61,7 +79,10 @@ class CliString(CliType):
     Takes a string value
     """
 
-    pass
+    default: Optional[str] = None
+    """
+    A default value, None if unknown
+    """
 
 
 @dataclass(unsafe_hash=True)
@@ -70,7 +91,10 @@ class CliBoolean(CliType):
     Takes a boolean value
     """
 
-    pass
+    default: Optional[bool] = None
+    """
+    A default value, None if unknown
+    """
 
 
 @dataclass(unsafe_hash=True)
@@ -79,7 +103,10 @@ class CliDir(CliType):
     Takes a directory path
     """
 
-    pass
+    default: Optional[str] = None
+    """
+    A default value, None if unknown
+    """
 
 
 @dataclass(unsafe_hash=True)
@@ -88,7 +115,10 @@ class CliFile(CliType):
     Takes a file path
     """
 
-    pass
+    default: Optional[str] = None
+    """
+    A default value, None if unknown
+    """
 
 
 @dataclass(unsafe_hash=True)
@@ -97,6 +127,11 @@ class CliDict(CliType):
     Takes a dictionary value
     """
 
+    default: Optional[str] = None
+    """
+    A default value, None if unknown
+    """
+
     key: CliType
     """
     Data type of the keys to this dictionary
@@ -114,6 +149,11 @@ class CliList(CliType):
     Takes a list value
     """
 
+    default: Optional[typing.List[CliType]] = None
+    """
+    A default value, None if unknown
+    """
+
     value: CliType
     """
     Data type of the values in this list
@@ -126,6 +166,12 @@ class CliTuple(CliType):
     Takes a list of values with a fixed length, possibly each with different types
     """
 
+    default: Optional[typing.Tuple[CliType]] = None
+
+    """
+    A default value, None if unknown
+    """
+
     values: typing.List[CliType]
     """
     List of types, in order, held within the tuple
diff --git a/acclimatise/model.py b/acclimatise/model.py
index 53eb03a..0745fa1 100644
--- a/acclimatise/model.py
+++ b/acclimatise/model.py
@@ -371,33 +371,48 @@ def capital(self):
         )
 
 
-int_re = re.compile("(int(eger)?)|size|length|max|min", flags=re.IGNORECASE)
+int_re = re.compile("(int(eger)?)|size|length|max|min|num(ber)?", flags=re.IGNORECASE)
 str_re = re.compile("str(ing)?", flags=re.IGNORECASE)
 float_re = re.compile("float|decimal", flags=re.IGNORECASE)
 bool_re = re.compile("bool(ean)?", flags=re.IGNORECASE)
 file_re = re.compile("file|path", flags=re.IGNORECASE)
 dir_re = re.compile("folder|directory", flags=re.IGNORECASE)
 
+default_re = re.compile(r"default(?: value)?(?:[:=] ?| )([^ )\]]+)", flags=re.IGNORECASE)
+
+float_re = re.compile('[+-]?([0-9]+([.][0-9]*)?|[.][0-9]+)', flags=re.IGNORECASE)
+int_re = re.compile('[+-]?([0-9]+[^.0-9])', flags=re.IGNORECASE)
+
 
 def infer_type(string) -> typing.Optional[cli_types.CliType]:
     """
     Reads a string (argument description etc) to find hints about what type this argument might be. This is
     generally called by the get_type() methods
     """
+    default_match = default_re.match()
+    if default_match is not None:
+        default = default_match.group(1)
+    else:
+        default = None
+
     if bool_re.match(string):
-        return cli_types.CliBoolean()
+        return cli_types.CliBoolean(default = default)
     elif float_re.match(string):
-        return cli_types.CliFloat()
+        return cli_types.CliFloat(default = default)
     elif int_re.match(string):
-        return cli_types.CliInteger()
+        return cli_types.CliInteger(default = default)
     elif file_re.match(string):
-        return cli_types.CliFile()
+        return cli_types.CliFile(default = default)
     elif dir_re.match(string):
-        return cli_types.CliDir()
+        return cli_types.CliDir(default = default)
     elif str_re.match(string):
-        return cli_types.CliString()
+        return cli_types.CliString(default = default)
+    elif float_re.search(string) and not int_re.search(string):
+        return cli_types.CliFloat(default = default)
+    elif not int_re.search(string) and int_re.search(string):
+        return cli_types.CliInteger(default = default)
     else:
-        return cli_types.CliString()
+        return cli_types.CliString(default = default)
 
 
 @yaml_object(yaml)