diff --git a/include/bx/constants.h b/include/bx/constants.h
index 9c6f4c8..5d8d011 100644
--- a/include/bx/constants.h
+++ b/include/bx/constants.h
@@ -20,9 +20,12 @@ namespace bx
 	/// The ratio of a circle's circumference to its radius. Pi multiplied by 2, or Tau. pi*2
 	constexpr float    kPi2            = 6.2831853071795864769252867665590f;
 
-	/// The reciprocal of pi. 1/pi
+	/// The reciprocal of kPi. 1/kPi
 	constexpr float    kInvPi          = 1.0f/kPi;
 
+	/// The reciprocal of kPi2. 1/kPi2
+	constexpr float    kInvPi2         = 1.0f/kPi2;
+
 	/// Pi divided by two. pi/2
 	constexpr float    kPiHalf         = 1.5707963267948966192313216916398f;
 
diff --git a/include/bx/inline/math.inl b/include/bx/inline/math.inl
index 183887b..684b162 100644
--- a/include/bx/inline/math.inl
+++ b/include/bx/inline/math.inl
@@ -164,7 +164,7 @@ namespace bx
 
 	inline void sinCosApprox(float _a, float* _outSin, float* _outCos)
 	{
-		const float aa     = _a - floor(_a/kPi2)*kPi2;
+		const float aa     = _a - floor(_a*kInvPi2)*kPi2;
 		const float absA   = abs(aa);
 		const float cosA   = cos(absA);
 		const float cosASq = square(cosA);