diff --git a/libs/math/include/psemek/math/math.hpp b/libs/math/include/psemek/math/math.hpp
index d29f14f9..f3e598ea 100644
--- a/libs/math/include/psemek/math/math.hpp
+++ b/libs/math/include/psemek/math/math.hpp
@@ -225,4 +225,10 @@ namespace psemek::math
 		return x * x * x * (10 - x * (15 - 6 * x));
 	}
 
+	template <typename T>
+	T inverse_smoothstep(T x)
+	{
+		return T{1} / T{2} - std::sin(std::asin(T{1} - T{2} * x) / T{3});
+	}
+
 }