diff --git a/src/rct2.h b/src/rct2.h
index b95864f69c..f5b765b206 100644
--- a/src/rct2.h
+++ b/src/rct2.h
@@ -64,7 +64,7 @@ typedef unsigned long long uint64;
 #define OPENRCT2_PLATFORM			"Windows"
 #define OPENRCT2_TIMESTAMP			__DATE__ " " __TIME__
 
-// Represent fixed point numbers
+// Represent fixed point numbers. dp = decimal point
 typedef sint16 fixed16_1dp;
 typedef sint16 fixed16_2dp;
 typedef sint32 fixed32_1dp;
@@ -74,7 +74,8 @@ typedef sint32 fixed32_2dp;
 typedef fixed16_1dp money16;
 typedef fixed32_1dp money32;
 
-// Construct a fixed point number.
+// Construct a fixed point number. For example, to create the value 3.65 you
+// would write FIXED_2DP(3,65)
 #define FIXED_XDP(x, whole, fraction)	((whole) * (10 * x) + (fraction))
 #define FIXED_1DP(whole, fraction)		FIXED_XDP(1, whole, fraction)
 #define FIXED_2DP(whole, fraction)		FIXED_XDP(2, whole, fraction)
diff --git a/src/ride.h b/src/ride.h
index 157cd72baf..5c1101e310 100644
--- a/src/ride.h
+++ b/src/ride.h
@@ -25,6 +25,8 @@
 
 typedef fixed16_2dp ride_rating;
 
+// Convenience function for writing ride ratings. The result is a 16 bit signed
+// integer. To create the ride rating 3.65 type RIDE_RATING(3,65)
 #define RIDE_RATING(whole, fraction)	FIXED_2DP(whole, fraction)
 
 // Used for return values, for functions that modify all three.