diff --git a/printed/foot.scad b/printed/foot.scad
index 2653662..5097f67 100644
--- a/printed/foot.scad
+++ b/printed/foot.scad
@@ -28,7 +28,6 @@ include <../vitamins/inserts.scad>
 foot        = [25, 12, 3, 2, M4_cap_screw, 10];
 insert_foot = [20, 10, 0, 2, M3_cap_screw, 10];
 
-function foot() = foot; //! Default foot used unless a list of parameters is passed
 function insert_foot() = insert_foot; //! Default foot with insert
 
 function foot_diameter(type = foot) = type[0]; //! Outside maximum diameter
diff --git a/readme.md b/readme.md
index c672a72..a609a38 100644
--- a/readme.md
+++ b/readme.md
@@ -3410,7 +3410,6 @@ inserts don't grip well in rubber.
 ### Functions
 | Function | Description |
 |:--- |:--- |
-| ```foot()``` | Default foot used unless a list of parameters is passed |
 | ```insert_foot()``` | Default foot with insert |
 
 ### Modules
@@ -4220,12 +4219,17 @@ Global constants, functions and modules. This file is used directly or indirectl
 | Function | Description |
 |:--- |:--- |
 | ```Len(x)``` | Returns the length of a list or 0 if ```x``` is not a list |
+| ```cm(x)``` | cm to mm conversion |
 | ```echoit(x)``` | Echo expression and return it, useful for debugging |
+| ```foot(x)``` | Foot to mm conversion |
 | ```in(list, x)``` | Returns true if ```x``` is an element in the ```list``` |
-| ```inch(x)``` | Inch to mm conversion |
+| ```inch(x)``` | Inch to mm conversion (For fractional inches, 'inch(1 + 7/8)' will work as expected.) |
+| ```m(x)``` | m to mm conversion |
+| ```mm(x)``` | Explicit mm specified |
 | ```r2sides(r)``` | Replicates the OpenSCAD logic to calculate the number of sides from the radius |
 | ```r2sides4n(r)``` | Round up the number of sides to a multiple of 4 to ensure points land on all axes |
 | ```sqr(x)``` | Returns the square of ```x``` |
+| ```yard(x)``` | Yard to mm conversion |
 
 ### Modules
 | Module | Description |
diff --git a/utils/core/global.scad b/utils/core/global.scad
index 2783c0c..13e3a39 100644
--- a/utils/core/global.scad
+++ b/utils/core/global.scad
@@ -22,8 +22,14 @@
 //
 include <../../global_defs.scad>
 
+function inch(x) = x * 25.4;                                                        //! Inch to mm conversion (For fractional inches, 'inch(1 + 7/8)' will work as expected.)
+function foot(x) = x * 25.4 * 12;                                                   //! Foot to mm conversion
+function yard(x) = x * 25.4 * 12 * 3;                                               //! Yard to mm conversion
+function mm(x)   = x;                                                               //! Explicit mm specified
+function cm(x)   = x * 10.0;                                                        //! cm to mm conversion
+function m(x)    = x * 1000.0;                                                      //! m to mm conversion
+
 function sqr(x) = x * x;                                                            //! Returns the square of ```x```
-function inch(x) = x * 25.4;                                                        //! Inch to mm conversion
 function echoit(x) = echo(x) x;                                                     //! Echo expression and return it, useful for debugging
 function in(list, x) = !!len([for(v = list) if(v == x) true]);                      //! Returns true if ```x``` is an element in the ```list```
 function Len(x) = is_list(x) ? len(x) : 0;                                          //! Returns the length of a list or 0 if ```x``` is not a list