Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Service/MacroStabilityInwardsInputValidator.cs
===================================================================
diff -u -r75739e1169b5ae12b686fe2f0d587468d9ea88b3 -r5236b25806d0dde12a0875c6aae87fb4e07c0c12
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Service/MacroStabilityInwardsInputValidator.cs	(.../MacroStabilityInwardsInputValidator.cs)	(revision 75739e1169b5ae12b686fe2f0d587468d9ea88b3)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Service/MacroStabilityInwardsInputValidator.cs	(.../MacroStabilityInwardsInputValidator.cs)	(revision 5236b25806d0dde12a0875c6aae87fb4e07c0c12)
@@ -40,7 +40,7 @@
     /// </summary>
     public static class MacroStabilityInwardsInputValidator
     {
-        private const double tolerance = 0.05;
+        private const double withinSurfaceLineLevelLimit = 0.05;
 
         /// <summary>
         /// Performs validation over the values on the given <paramref name="inputParameters"/>.
@@ -136,7 +136,7 @@
             double layerTop = soilProfile1D.Layers.Max(l => l.Top);
             double surfaceLineTop = inputParameters.SurfaceLine.LocalGeometry.Max(p => p.Y);
 
-            return layerTop + tolerance >= surfaceLineTop;
+            return layerTop + withinSurfaceLineLevelLimit >= surfaceLineTop;
         }
 
         private static bool ValidateSurfaceLineIsNearSoilProfile(MacroStabilityInwardsInput inputParameters,
@@ -157,7 +157,7 @@
                 }
 
                 double maxYCoordinate = intersectingCoordinates.Select(p => p.Y).Max();
-                if (Math.Abs(surfaceLinePoint.Y - maxYCoordinate) > tolerance)
+                if (Math.Abs(surfaceLinePoint.Y - maxYCoordinate) - withinSurfaceLineLevelLimit >= 1e-5)
                 {
                     return false;
                 }
@@ -172,29 +172,29 @@
             IEnumerable<double> surfaceLineXCoordinates = surfaceLinePoints.Select(p => p.X).ToArray();
             IEnumerable<double> soilProfileXCoordinates = GetSoilProfile2DXCoordinates(soilProfile2D).ToArray();
 
-            double maxXCoordinate = surfaceLineXCoordinates.Max() < soilProfileXCoordinates.Max()
-                                        ? surfaceLineXCoordinates.Max()
-                                        : soilProfileXCoordinates.Max();
+            double maximumXCoordinateSurfaceLine = surfaceLineXCoordinates.Max();
+            double maximumXCoordinateSoilProfile = soilProfileXCoordinates.Max();
+            double maxXCoordinate = Math.Min(maximumXCoordinateSoilProfile, maximumXCoordinateSurfaceLine);
 
             var xCoordinates = new List<double>();
-            double x = surfaceLineXCoordinates.Min() < soilProfileXCoordinates.Min()
-                           ? surfaceLineXCoordinates.Min()
-                           : soilProfileXCoordinates.Min();
+            double minimumXCoordinateSurfaceLine = surfaceLineXCoordinates.Min();
+            double minimumXCoordinateSoilProfile = soilProfileXCoordinates.Min();
+            double x = Math.Max(minimumXCoordinateSoilProfile, minimumXCoordinateSurfaceLine);
             while (x < maxXCoordinate)
             {
                 xCoordinates.Add(x);
-                x += tolerance;
+                x += withinSurfaceLineLevelLimit;
             }
+            xCoordinates.Add(maxXCoordinate);
 
             return xCoordinates;
         }
 
         private static IEnumerable<IEnumerable<Segment2D>> GetLayerPolygons(MacroStabilityInwardsSoilProfile2D soilProfile2D)
         {
-            IEnumerable<IEnumerable<Segment2D>> layerPolygons = soilProfile2D.Layers
-                                                                             .Select(l => Math2D.ConvertPointsToPolygonSegments(l.OuterRing.Points))
-                                                                             .ToArray();
-            return layerPolygons;
+            return soilProfile2D.Layers
+                                .Select(l => Math2D.ConvertPointsToPolygonSegments(l.OuterRing.Points))
+                                .ToArray();
         }
 
         private static IEnumerable<double> GetSoilProfile2DXCoordinates(MacroStabilityInwardsSoilProfile2D soilProfile2D)
Index: Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.Service.Test/MacroStabilityInwardsInputValidatorTest.cs
===================================================================
diff -u -r75739e1169b5ae12b686fe2f0d587468d9ea88b3 -r5236b25806d0dde12a0875c6aae87fb4e07c0c12
--- Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.Service.Test/MacroStabilityInwardsInputValidatorTest.cs	(.../MacroStabilityInwardsInputValidatorTest.cs)	(revision 75739e1169b5ae12b686fe2f0d587468d9ea88b3)
+++ Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.Service.Test/MacroStabilityInwardsInputValidatorTest.cs	(.../MacroStabilityInwardsInputValidatorTest.cs)	(revision 5236b25806d0dde12a0875c6aae87fb4e07c0c12)
@@ -794,7 +794,7 @@
                             })),
                             new MacroStabilityInwardsSoilLayer2D(new Ring(new[]
                             {
-                                new Point2D(0, 10.0 - 0.05),
+                                new Point2D(0, 10.0 - 0.06),
                                 new Point2D(1, 20)
                             }))
                         }, new MacroStabilityInwardsPreconsolidationStress[0]))
@@ -813,7 +813,7 @@
                             })),
                             new MacroStabilityInwardsSoilLayer2D(new Ring(new[]
                             {
-                                new Point2D(0, 10.0 + 0.05),
+                                new Point2D(0, 10.0 + 0.06),
                                 new Point2D(1, 20)
                             }))
                         }, new MacroStabilityInwardsPreconsolidationStress[0]))
@@ -909,7 +909,7 @@
                             })),
                             new MacroStabilityInwardsSoilLayer2D(new Ring(new[]
                             {
-                                new Point2D(0.0, 10.0049),
+                                new Point2D(0.0, 10 + 0.05),
                                 new Point2D(0.1, 20)
                             }))
                         }, new MacroStabilityInwardsPreconsolidationStress[0]))
@@ -928,7 +928,7 @@
                             })),
                             new MacroStabilityInwardsSoilLayer2D(new Ring(new[]
                             {
-                                new Point2D(0.0, 10.0 - 0.0049),
+                                new Point2D(0.0, 10.0 - 0.05),
                                 new Point2D(0.1, 20)
                             }))
                         }, new MacroStabilityInwardsPreconsolidationStress[0]))
@@ -988,9 +988,9 @@
                         {
                             new MacroStabilityInwardsSoilLayer2D(new Ring(new[]
                             {
-                                new Point2D(0.0, 10.04),
-                                new Point2D(0.1, 20.04),
-                                new Point2D(0.2, 10.04)
+                                new Point2D(0.0, 10.0 + 0.05),
+                                new Point2D(0.1, 20.0 + 0.05),
+                                new Point2D(0.2, 10.0 + 0.05)
                             })),
                             new MacroStabilityInwardsSoilLayer2D(new Ring(new[]
                             {
@@ -1020,6 +1020,36 @@
                             }))
                         }, new MacroStabilityInwardsPreconsolidationStress[0]))
                 .SetName("Top soilLayer offset below surfaceline within limit");
+
+            yield return new TestCaseData(
+                    new MacroStabilityInwardsSoilProfile2D(
+                        "profile",
+                        new[]
+                        {
+                            new MacroStabilityInwardsSoilLayer2D(new Ring(new[]
+                            {
+                                new Point2D(0.0, 10),
+                                new Point2D(0.1, 20),
+                                new Point2D(0.2, 10),
+                                new Point2D(0.25, 10)
+                            }))
+                        }, new MacroStabilityInwardsPreconsolidationStress[0]))
+                .SetName("Max X soilLayer larger than surface line");
+
+            yield return new TestCaseData(
+                    new MacroStabilityInwardsSoilProfile2D(
+                        "profile",
+                        new[]
+                        {
+                            new MacroStabilityInwardsSoilLayer2D(new Ring(new[]
+                            {
+                                new Point2D(-0.1, 10),
+                                new Point2D(0.0, 10),
+                                new Point2D(0.1, 20),
+                                new Point2D(0.2, 10)
+                            }))
+                        }, new MacroStabilityInwardsPreconsolidationStress[0]))
+                .SetName("Min X soilLayer smaller than surface line");
         }
 
         private static RoundedDouble GetTestNormativeAssessmentLevel()