diff --git a/config.h.dist b/config.h.dist
index b0c33f7..484ec60 100644
--- a/config.h.dist
+++ b/config.h.dist
@@ -3,19 +3,19 @@
 
 /*
 	Values reflecting the gearing of your machine.
-		All numbers are integers, so no decimals, please :-)
+		All numbers are fixed point integers, so no more than 3 digits to the right of the decimal point, please :-)
 */
 
 // calculate these values appropriate for your machine
 // for threaded rods, this is (steps motor per turn) / (pitch of the thread)
 // for belts, this is (steps per motor turn) / (number of gear teeth) / (belt module)
 // half-stepping doubles the number, quarter stepping requires * 4, etc.
-#define	STEPS_PER_MM_X				320
-#define	STEPS_PER_MM_Y				320
-#define	STEPS_PER_MM_Z				320
+#define	STEPS_PER_MM_X				320.000
+#define	STEPS_PER_MM_Y				320.000
+#define	STEPS_PER_MM_Z				320.000
 
 // http://blog.arcol.hu/?p=157 may help with this next one
-#define	STEPS_PER_MM_E				320
+#define	STEPS_PER_MM_E				320.000
 
 /*
 	Values depending on the capabilities of your stepper motors and other mechanics.
diff --git a/gcode.c b/gcode.c
index 9b47164..42c16c4 100644
--- a/gcode.c
+++ b/gcode.c
@@ -15,9 +15,29 @@
 #include	"heater.h"
 #include	"sersendf.h"
 
+/*
+	Switch user friendly values to coding friendly values
+
+	This also affects the possible build volume. We have +-2^31 numbers available and as we internally measure position in steps and use a precision factor of 1000, this translates into a possible range of
+
+		2^31 mm / STEPS_PER_MM_x / 1000
+
+	for each axis. For a M6 threaded rod driven machine and 1/16 microstepping this evaluates to
+
+		2^31 mm / 200 / 1 / 16 / 1000 = 671 mm,
+
+	which is about the worst case we have. All other machines have a bigger build volume.
+*/
+
+#define	STEPS_PER_M_X			((uint32_t) (STEPS_PER_MM_X * 1000.0))
+#define	STEPS_PER_M_Y			((uint32_t) (STEPS_PER_MM_Y * 1000.0))
+#define	STEPS_PER_M_Z			((uint32_t) (STEPS_PER_MM_Z * 1000.0))
+#define	STEPS_PER_M_E			((uint32_t) (STEPS_PER_MM_E * 1000.0))
+
 /*
 	mm -> inch conversion
 */
+
 #define	STEPS_PER_IN_X		((uint32_t) ((25.4 * STEPS_PER_MM_X) + 0.5))
 #define	STEPS_PER_IN_Y		((uint32_t) ((25.4 * STEPS_PER_MM_Y) + 0.5))
 #define	STEPS_PER_IN_Z		((uint32_t) ((25.4 * STEPS_PER_MM_Z) + 0.5))
@@ -133,7 +153,7 @@ void scan_char(uint8_t c) {
 					if (next_target.option_inches)
 						next_target.target.X = decfloat_to_int(&read_digit, STEPS_PER_IN_X, 1);
 					else
-						next_target.target.X = decfloat_to_int(&read_digit, STEPS_PER_MM_X, 1);
+						next_target.target.X = decfloat_to_int(&read_digit, STEPS_PER_M_X, 1000);
 					if (debug_flags & DEBUG_ECHO)
 						serwrite_int32(next_target.target.X);
 					break;
@@ -141,7 +161,7 @@ void scan_char(uint8_t c) {
 					if (next_target.option_inches)
 						next_target.target.Y = decfloat_to_int(&read_digit, STEPS_PER_IN_Y, 1);
 					else
-						next_target.target.Y = decfloat_to_int(&read_digit, STEPS_PER_MM_Y, 1);
+						next_target.target.Y = decfloat_to_int(&read_digit, STEPS_PER_M_Y, 1000);
 					if (debug_flags & DEBUG_ECHO)
 						serwrite_int32(next_target.target.Y);
 					break;
@@ -149,7 +169,7 @@ void scan_char(uint8_t c) {
 					if (next_target.option_inches)
 						next_target.target.Z = decfloat_to_int(&read_digit, STEPS_PER_IN_Z, 1);
 					else
-						next_target.target.Z = decfloat_to_int(&read_digit, STEPS_PER_MM_Z, 1);
+						next_target.target.Z = decfloat_to_int(&read_digit, STEPS_PER_M_Z, 1000);
 					if (debug_flags & DEBUG_ECHO)
 						serwrite_int32(next_target.target.Z);
 					break;
@@ -157,7 +177,7 @@ void scan_char(uint8_t c) {
 					if (next_target.option_inches)
 						next_target.target.E = decfloat_to_int(&read_digit, STEPS_PER_IN_E, 1);
 					else
-						next_target.target.E = decfloat_to_int(&read_digit, STEPS_PER_MM_E, 1);
+						next_target.target.E = decfloat_to_int(&read_digit, STEPS_PER_M_E, 1000);
 					if (debug_flags & DEBUG_ECHO)
 						serwrite_uint32(next_target.target.E);
 					break;