Index: Riskeer/Revetment/src/Riskeer.Revetment.Data/Properties/Resources.Designer.cs
===================================================================
diff -u -rd1b677c4bef119458dc4ec64058c68dd508578e3 -rca27aad321f52f827c76143342c222946e587f7f
--- Riskeer/Revetment/src/Riskeer.Revetment.Data/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision d1b677c4bef119458dc4ec64058c68dd508578e3)
+++ Riskeer/Revetment/src/Riskeer.Revetment.Data/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision ca27aad321f52f827c76143342c222946e587f7f)
@@ -82,6 +82,15 @@
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to De waarde voor de stapgrootte moet in het bereik {0} liggen..
+        /// </summary>
+        internal static string StepSize_Value_needs_to_be_in_Range_0_ {
+            get {
+                return ResourceManager.GetString("StepSize_Value_needs_to_be_in_Range_0_", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to De bovengrens van de bekleding moet boven de ondergrens liggen..
         /// </summary>
         internal static string WaveConditionsInput_ValidateRevetmentBoundaries_Upper_boundary_revetment_must_be_above_lower_boundary_revetment {
Index: Riskeer/Revetment/src/Riskeer.Revetment.Data/Properties/Resources.resx
===================================================================
diff -u -rbf1fde9d2147a6eeaecebbb371be2c4856759159 -rca27aad321f52f827c76143342c222946e587f7f
--- Riskeer/Revetment/src/Riskeer.Revetment.Data/Properties/Resources.resx	(.../Resources.resx)	(revision bf1fde9d2147a6eeaecebbb371be2c4856759159)
+++ Riskeer/Revetment/src/Riskeer.Revetment.Data/Properties/Resources.resx	(.../Resources.resx)	(revision ca27aad321f52f827c76143342c222946e587f7f)
@@ -132,4 +132,7 @@
   <data name="WaveConditionsInputStepSize_Two" xml:space="preserve">
     <value>2.0</value>
   </data>
+  <data name="StepSize_Value_needs_to_be_in_Range_0_" xml:space="preserve">
+    <value>De waarde voor de stapgrootte moet in het bereik {0} liggen.</value>
+  </data>
 </root>
\ No newline at end of file
Index: Riskeer/Revetment/src/Riskeer.Revetment.Data/WaveConditionsInput.cs
===================================================================
diff -u -rd1b677c4bef119458dc4ec64058c68dd508578e3 -rca27aad321f52f827c76143342c222946e587f7f
--- Riskeer/Revetment/src/Riskeer.Revetment.Data/WaveConditionsInput.cs	(.../WaveConditionsInput.cs)	(revision d1b677c4bef119458dc4ec64058c68dd508578e3)
+++ Riskeer/Revetment/src/Riskeer.Revetment.Data/WaveConditionsInput.cs	(.../WaveConditionsInput.cs)	(revision ca27aad321f52f827c76143342c222946e587f7f)
@@ -44,12 +44,18 @@
             new RoundedDouble(orientationNumberOfDecimals),
             new RoundedDouble(orientationNumberOfDecimals, 360));
 
+        private const int stepSizeNumberOfDecimals = 2;
+        private static readonly Range<RoundedDouble> stepSizeValidityRange = new Range<RoundedDouble>(
+            new RoundedDouble(stepSizeNumberOfDecimals, 0.01),
+            new RoundedDouble(stepSizeNumberOfDecimals, 2.0));
+        
         private ForeshoreProfile foreshoreProfile;
         private RoundedDouble upperBoundaryRevetment;
         private RoundedDouble lowerBoundaryRevetment;
         private RoundedDouble upperBoundaryWaterLevels;
         private RoundedDouble lowerBoundaryWaterLevels;
         private RoundedDouble orientation;
+        private RoundedDouble stepSize;
 
         /// <summary>
         /// Creates a new instance of <see cref="WaveConditionsInput"/>.
@@ -60,7 +66,7 @@
 
             upperBoundaryRevetment = new RoundedDouble(2, double.NaN);
             lowerBoundaryRevetment = new RoundedDouble(2, double.NaN);
-            StepSize = WaveConditionsInputStepSize.Half;
+            stepSize = new RoundedDouble(stepSizeNumberOfDecimals, 0.5);
             upperBoundaryWaterLevels = new RoundedDouble(2, double.NaN);
             lowerBoundaryWaterLevels = new RoundedDouble(2, double.NaN);
             WaterLevelType = WaveConditionsInputWaterLevelType.None;
@@ -133,8 +139,22 @@
         /// <summary>
         /// Gets or sets the step size used for determining water levels.
         /// </summary>
-        public WaveConditionsInputStepSize StepSize { get; set; }
+        public RoundedDouble StepSize
+        {
+            get => stepSize;
+            set
+            {
+                RoundedDouble newStepSize = value.ToPrecision(stepSizeNumberOfDecimals);
+                if (double.IsNaN(newStepSize) || !stepSizeValidityRange.InRange(newStepSize))
+                {
+                    throw new ArgumentOutOfRangeException(null, string.Format(Resources.StepSize_Value_needs_to_be_in_Range_0_,
+                                                                              stepSizeValidityRange));
+                }
 
+                stepSize = newStepSize;
+            }
+        }
+
         /// <summary>
         /// Gets or sets the lower boundary of the water levels range.
         /// </summary>
Index: Riskeer/Revetment/test/Riskeer.Revetment.Data.Test/WaveConditionsInputTest.cs
===================================================================
diff -u -rd1b677c4bef119458dc4ec64058c68dd508578e3 -rca27aad321f52f827c76143342c222946e587f7f
--- Riskeer/Revetment/test/Riskeer.Revetment.Data.Test/WaveConditionsInputTest.cs	(.../WaveConditionsInputTest.cs)	(revision d1b677c4bef119458dc4ec64058c68dd508578e3)
+++ Riskeer/Revetment/test/Riskeer.Revetment.Data.Test/WaveConditionsInputTest.cs	(.../WaveConditionsInputTest.cs)	(revision ca27aad321f52f827c76143342c222946e587f7f)
@@ -68,7 +68,8 @@
             Assert.AreEqual(2, input.LowerBoundaryWaterLevels.NumberOfDecimalPlaces);
             Assert.IsNaN(input.UpperBoundaryWaterLevels.Value);
             Assert.AreEqual(2, input.UpperBoundaryWaterLevels.NumberOfDecimalPlaces);
-            Assert.AreEqual(WaveConditionsInputStepSize.Half, input.StepSize);
+            Assert.AreEqual(0.5, input.StepSize);
+            Assert.AreEqual(2, input.StepSize.NumberOfDecimalPlaces);
             Assert.AreEqual(WaveConditionsInputWaterLevelType.None, input.WaterLevelType);
             Assert.IsNull(input.CalculationsTargetProbability);
         }
@@ -337,6 +338,46 @@
         }
 
         [Test]
+        [TestCase(2.004)]
+        [TestCase(2.0)]
+        [TestCase(0.01)]
+        [TestCase(0.005)]
+        public void StepSize_ValidValue_NewValueSet(double stepSize)
+        {
+            // Setup
+            var input = new WaveConditionsInput();
+
+            // Call
+            input.StepSize = (RoundedDouble) stepSize;
+
+            // Assert
+            Assert.AreEqual(2, input.StepSize.NumberOfDecimalPlaces);
+            Assert.AreEqual(stepSize, input.StepSize, input.StepSize.GetAccuracy());
+        }
+
+        [Test]
+        [SetCulture("nl-NL")]
+        [TestCase(double.NaN)]
+        [TestCase(5)]
+        [TestCase(2.01)]
+        [TestCase(0.004)]
+        [TestCase(0)]
+        [TestCase(double.PositiveInfinity)]
+        [TestCase(double.NegativeInfinity)]
+        public void StepSize_InvalidValue_ThrowsArgumentOutOfRangeException(double invalidValue)
+        {
+            // Setup
+            var input = new WaveConditionsInput();
+
+            // Call
+            void Call() => input.StepSize = (RoundedDouble) invalidValue;
+
+            // Assert
+            const string message = "De waarde voor de stapgrootte moet in het bereik [0,01, 2,00] liggen.";
+            TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentOutOfRangeException>(Call, message);
+        }
+        
+        [Test]
         public void LowerBoundaryRevetment_SetNewValue_ValueIsRounded()
         {
             // Setup