Index: Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Data/GrassCoverErosionInwardsInput.cs
===================================================================
diff -u -rb2b9fdf365e70928a05c57966eeed30d9050e528 -r974fb1eadbd8a630c7a992648ad42ac85ec205b1
--- Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Data/GrassCoverErosionInwardsInput.cs	(.../GrassCoverErosionInwardsInput.cs)	(revision b2b9fdf365e70928a05c57966eeed30d9050e528)
+++ Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Data/GrassCoverErosionInwardsInput.cs	(.../GrassCoverErosionInwardsInput.cs)	(revision 974fb1eadbd8a630c7a992648ad42ac85ec205b1)
@@ -38,6 +38,11 @@
     public class GrassCoverErosionInwardsInput : Observable, ICalculationInput, IUseBreakWater,
                                                  IUseForeshore
     {
+        private const int orientationNumberOfDecimals = 2;
+
+        private static readonly Range<RoundedDouble> orientationValidityRange = new Range<RoundedDouble>(new RoundedDouble(orientationNumberOfDecimals),
+                                                                                                         new RoundedDouble(orientationNumberOfDecimals, 360));
+
         private readonly LogNormalDistribution criticalFlowRate;
         private RoundedDouble orientation;
         private RoundedDouble dikeHeight;
@@ -48,7 +53,7 @@
         /// </summary>
         public GrassCoverErosionInwardsInput()
         {
-            orientation = new RoundedDouble(2);
+            orientation = new RoundedDouble(orientationNumberOfDecimals);
             dikeHeight = new RoundedDouble(2);
 
             UpdateProfileParameters();
@@ -90,9 +95,10 @@
             set
             {
                 RoundedDouble newOrientation = value.ToPrecision(orientation.NumberOfDecimalPlaces);
-                if (!double.IsNaN(newOrientation) && (newOrientation < 0 || newOrientation > 360))
+                if (!double.IsNaN(newOrientation) && !orientationValidityRange.InRange(newOrientation))
                 {
-                    throw new ArgumentOutOfRangeException(nameof(value), RingtoetsCommonDataResources.Orientation_Value_needs_to_be_between_0_and_360);
+                    throw new ArgumentOutOfRangeException(nameof(value), string.Format(RingtoetsCommonDataResources.Orientation_Value_needs_to_be_in_Range_0_,
+                                                                                       orientationValidityRange));
                 }
                 orientation = newOrientation;
             }