diff --git a/Easing/Easing.cs b/Easing/Easing.cs
index 6ac25c4..b0a08bc 100644
--- a/Easing/Easing.cs
+++ b/Easing/Easing.cs
@@ -158,5 +158,49 @@ namespace MoonTools.Core.Easing
                 return InQuad((t * 2) - d, b + c / 2, c / 2, d);
             }
         }
+
+        // IN CUBIC
+
+        public static float InCubic(float t) => NormalizedTime(InCubic, t);
+        public static float InCubic(float time, float start, float end) => TimeRange(InCubic, time, start, end);
+
+        public static float InCubic(float t, float b, float c, float d)
+        {
+            CheckTime(t, d);
+            t = t / d;
+            return c * (t * t * t) + b;
+        }
+
+        public static double InCubic(double t) => NormalizedTime(InCubic, t);
+        public static double InCubic(double time, double start, double end) => TimeRange(InCubic, time, start, end);
+
+        public static double InCubic(double t, double b, double c, double d)
+        {
+            CheckTime(t, d);
+            t = t / d;
+            return c * (t * t * t) + b;
+        }
+
+        // OUT CUBIC
+
+        public static float OutCubic(float t) => NormalizedTime(OutCubic, t);
+        public static float OutCubic(float time, float start, float end) => TimeRange(OutCubic, time, start, end);
+
+        public static float OutCubic(float t, float b, float c, float d)
+        {
+            CheckTime(t, d);
+            t = t / d - 1;
+            return c * (t * t * t + 1) + b;
+        }
+
+        public static double OutCubic(double t) => NormalizedTime(OutCubic, t);
+        public static double OutCubic(double time, double start, double end) => TimeRange(OutCubic, time, start, end);
+
+        public static double OutCubic(double t, double b, double c, double d)
+        {
+            CheckTime(t, d);
+            t = t / d - 1;
+            return c * (t * t * t + 1) + b;
+        }
     }
 }
diff --git a/Test/Easing.cs b/Test/Easing.cs
index df9a951..c3e4a48 100644
--- a/Test/Easing.cs
+++ b/Test/Easing.cs
@@ -138,6 +138,9 @@ namespace Test
             Easing.OutInQuad(0.5).Should().Be(0.5);
             Easing.OutInQuad(0.75).Should().Be(0.625);
 
+            invalidTime = () => Easing.OutInQuad(1.5);
+            invalidTime.Should().Throw<ArgumentException>();
+
             Easing.OutInQuad(3, 2, 6).Should().Be(3.5f);
             Easing.OutInQuad(4, 2, 6).Should().Be(4f);
             Easing.OutInQuad(5, 2, 6).Should().Be(4.5f);
@@ -149,5 +152,63 @@ namespace Test
             Easing.OutInQuad(4.0, 2, 6).Should().Be(4);
             Easing.OutInQuad(5.0, 2, 6).Should().Be(4.5);
         }
+
+        [Test]
+        public void InCubic()
+        {
+            Easing.InCubic(0.25f).Should().Be(0.015625f);
+            Easing.InCubic(0.5f).Should().Be(0.125f);
+            Easing.InCubic(0.75f).Should().Be(0.421875f);
+
+            Action invalidTime = () => Easing.InCubic(1.5f);
+            invalidTime.Should().Throw<ArgumentException>();
+
+            Easing.InCubic(0.25).Should().Be(0.015625);
+            Easing.InCubic(0.5).Should().Be(0.125);
+            Easing.InCubic(0.75).Should().Be(0.421875);
+
+            invalidTime = () => Easing.InCubic(1.5);
+            invalidTime.Should().Throw<ArgumentException>();
+
+            Easing.InCubic(3, 2, 6).Should().Be(2.0625f);
+            Easing.InCubic(4, 2, 6).Should().Be(2.5f);
+            Easing.InCubic(5, 2, 6).Should().Be(3.6875f);
+
+            invalidTime = () => Easing.InCubic(7, 2, 6);
+            invalidTime.Should().Throw<ArgumentException>();
+
+            Easing.InCubic(3.0, 2, 6).Should().Be(2.0625);
+            Easing.InCubic(4.0, 2, 6).Should().Be(2.5);
+            Easing.InCubic(5.0, 2, 6).Should().Be(3.6875);
+        }
+
+        [Test]
+        public void OutCubic()
+        {
+            Easing.OutCubic(0.25f).Should().Be(0.578125f);
+            Easing.OutCubic(0.5f).Should().Be(0.875f);
+            Easing.OutCubic(0.75f).Should().Be(0.984375f);
+
+            Action invalidTime = () => Easing.OutCubic(1.5);
+            invalidTime.Should().Throw<ArgumentException>();
+
+            Easing.OutCubic(0.25).Should().Be(0.578125);
+            Easing.OutCubic(0.5).Should().Be(0.875);
+            Easing.OutCubic(0.75).Should().Be(0.984375);
+
+            invalidTime = () => Easing.OutCubic(1.5);
+            invalidTime.Should().Throw<ArgumentException>();
+
+            Easing.OutCubic(3, 2, 6).Should().Be(4.3125f);
+            Easing.OutCubic(4, 2, 6).Should().Be(5.5f);
+            Easing.OutCubic(5, 2, 6).Should().Be(5.9375f);
+
+            invalidTime = () => Easing.OutCubic(7, 2, 6);
+            invalidTime.Should().Throw<ArgumentException>();
+
+            Easing.OutCubic(3.0, 2, 6).Should().Be(4.3125);
+            Easing.OutCubic(4.0, 2, 6).Should().Be(5.5);
+            Easing.OutCubic(5.0, 2, 6).Should().Be(5.9375);
+        }
     }
 }
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