diff --git a/src/BizHawk.Client.Common/tools/Cheat.cs b/src/BizHawk.Client.Common/tools/Cheat.cs
index 1840449e18..227c0b5626 100644
--- a/src/BizHawk.Client.Common/tools/Cheat.cs
+++ b/src/BizHawk.Client.Common/tools/Cheat.cs
@@ -91,35 +91,20 @@ namespace BizHawk.Client.Common
 
 		public string AddressStr => _watch.AddressString;
 
-		public string ValueStr =>
-			_watch.Size switch
-				{
-					WatchSize.Byte => ((ByteWatch) _watch).FormatValue((byte)_val),
-					WatchSize.Word => ((WordWatch) _watch).FormatValue((ushort)_val),
-					WatchSize.DWord => ((DWordWatch) _watch).FormatValue((uint)_val),
-					WatchSize.Separator => "",
-					_ => string.Empty,
-				};
+		public string ValueStr
+			=> _watch.Size is WatchSize.Byte or WatchSize.Word or WatchSize.DWord
+				? _watch.IsValid
+					? Watch.FormatValue(unchecked((uint) _val), _watch.Size, _watch.Type)
+					: "-"
+				: string.Empty;
 
 		public string CompareStr
-		{
-			get
-			{
-				if (_compare.HasValue)
-				{
-					return _watch.Size switch
-					{
-						WatchSize.Byte => ((ByteWatch) _watch).FormatValue((byte)_compare.Value),
-						WatchSize.Word => ((WordWatch) _watch).FormatValue((ushort)_compare.Value),
-						WatchSize.DWord => ((DWordWatch) _watch).FormatValue((uint)_compare.Value),
-						WatchSize.Separator => "",
-						_ => string.Empty,
-					};
-				}
-
-				return "";
-			}
-		}
+			=> _compare.Value is int compareValue
+				&& _watch.Size is WatchSize.Byte or WatchSize.Word or WatchSize.DWord
+					? _watch.IsValid
+						? Watch.FormatValue(unchecked((uint) compareValue), _watch.Size, _watch.Type)
+						: "-"
+					: string.Empty;
 
 		public CompareType ComparisonType { get; }
 
diff --git a/src/BizHawk.Client.Common/tools/Watch/ByteWatch.cs b/src/BizHawk.Client.Common/tools/Watch/ByteWatch.cs
index 3fb72c3faf..d2480d7c45 100644
--- a/src/BizHawk.Client.Common/tools/Watch/ByteWatch.cs
+++ b/src/BizHawk.Client.Common/tools/Watch/ByteWatch.cs
@@ -1,5 +1,5 @@
 using System.Collections.Generic;
-using System.Globalization;
+
 using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.Common
@@ -56,16 +56,7 @@ namespace BizHawk.Client.Common
 		{
 			try
 			{
-				byte val = Type switch
-				{
-					WatchDisplayType.Unsigned => byte.Parse(value),
-					WatchDisplayType.Signed => (byte)sbyte.Parse(value),
-					WatchDisplayType.Hex => byte.Parse(value, NumberStyles.HexNumber),
-					WatchDisplayType.Binary => Convert.ToByte(value, 2),
-					_ => 0,
-				};
-
-				PokeByte(val);
+				PokeByte(unchecked((byte) Watch.ParseValue(value, Size, Type)));
 				return true;
 			}
 			catch
@@ -104,17 +95,7 @@ namespace BizHawk.Client.Common
 
 		// TODO: Implements IFormattable
 		public string FormatValue(byte val)
-		{
-			return Type switch
-			{
-				_ when !IsValid => "-",
-				WatchDisplayType.Unsigned => val.ToString(),
-				WatchDisplayType.Signed => ((sbyte) val).ToString(),
-				WatchDisplayType.Hex => $"{val:X2}",
-				WatchDisplayType.Binary => Convert.ToString(val, 2).PadLeft(8, '0').Insert(4, " "),
-				_ => val.ToString(),
-			};
-		}
+			=> IsValid ? Watch.FormatValue(val, Size, Type) : "-";
 
 		public override string Diff => $"{_value - _previous:+#;-#;0}";
 
diff --git a/src/BizHawk.Client.Common/tools/Watch/DWordWatch.cs b/src/BizHawk.Client.Common/tools/Watch/DWordWatch.cs
index 9d9ab5e781..9096a72911 100644
--- a/src/BizHawk.Client.Common/tools/Watch/DWordWatch.cs
+++ b/src/BizHawk.Client.Common/tools/Watch/DWordWatch.cs
@@ -1,6 +1,5 @@
 using System.Collections.Generic;
-using System.Globalization;
-using BizHawk.Common.NumberExtensions;
+
 using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.Common
@@ -58,19 +57,7 @@ namespace BizHawk.Client.Common
 		{
 			try
 			{
-				uint val = Type switch
-				{
-					WatchDisplayType.Unsigned => uint.Parse(value),
-					WatchDisplayType.Signed => (uint)int.Parse(value),
-					WatchDisplayType.Hex => uint.Parse(value, NumberStyles.HexNumber),
-					WatchDisplayType.FixedPoint_20_12 => (uint)(double.Parse(value, NumberFormatInfo.InvariantInfo) * 4096.0),
-					WatchDisplayType.FixedPoint_16_16 => (uint)(double.Parse(value, NumberFormatInfo.InvariantInfo) * 65536.0),
-					WatchDisplayType.Float => NumberExtensions.ReinterpretAsUInt32(float.Parse(value, NumberFormatInfo.InvariantInfo)),
-					WatchDisplayType.Binary => Convert.ToUInt32(value, 2),
-					_ => 0,
-				};
-
-				PokeDWord(val);
+				PokeDWord(Watch.ParseValue(value, Size, Type));
 				return true;
 			}
 			catch
@@ -109,36 +96,7 @@ namespace BizHawk.Client.Common
 
 		// TODO: Implements IFormattable
 		public string FormatValue(uint val)
-		{
-			string FormatFloat()
-			{
-				var _float = NumberExtensions.ReinterpretAsF32(val);
-				return _float.ToString(NumberFormatInfo.InvariantInfo);
-			}
-
-			string FormatBinary()
-			{
-				var str = Convert.ToString(val, 2).PadLeft(32, '0');
-				for (var i = 28; i > 0; i -= 4)
-				{
-					str = str.Insert(i, " ");
-				}
-				return str;
-			}
-
-			return Type switch
-			{
-				_ when !IsValid => "-",
-				WatchDisplayType.Unsigned => val.ToString(),
-				WatchDisplayType.Signed => ((int)val).ToString(),
-				WatchDisplayType.Hex => $"{val:X8}",
-				WatchDisplayType.FixedPoint_20_12 => ((int)val / 4096.0).ToString("0.######", NumberFormatInfo.InvariantInfo),
-				WatchDisplayType.FixedPoint_16_16 => ((int)val / 65536.0).ToString("0.######", NumberFormatInfo.InvariantInfo),
-				WatchDisplayType.Float => FormatFloat(),
-				WatchDisplayType.Binary => FormatBinary(),
-				_ => val.ToString(),
-			};
-		}
+			=> IsValid ? Watch.FormatValue(val, Size, Type) : "-";
 
 		public override string Diff => $"{_value - (long)_previous:+#;-#;0}";
 
diff --git a/src/BizHawk.Client.Common/tools/Watch/Watch.cs b/src/BizHawk.Client.Common/tools/Watch/Watch.cs
index 1405123cfd..c9a2c79990 100644
--- a/src/BizHawk.Client.Common/tools/Watch/Watch.cs
+++ b/src/BizHawk.Client.Common/tools/Watch/Watch.cs
@@ -19,6 +19,78 @@ namespace BizHawk.Client.Common
 		IEquatable<Cheat>,
 		IComparable<Watch>
 	{
+		private const string ERR_MSG_INVALID_WIDTH = "can only parse numeric strings for 1-, 2-, or 4-octet watches";
+
+		public static string FormatValue(uint value, WatchSize width, WatchDisplayType dispType)
+			=> width switch
+			{
+				WatchSize.Byte => dispType switch
+				{
+					WatchDisplayType.Signed => unchecked((sbyte) value).ToString(),
+					WatchDisplayType.Unsigned => value.ToString(),
+					WatchDisplayType.Hex => $"{value:X2}",
+					WatchDisplayType.Binary => Convert.ToString(unchecked((byte) value), toBase: 2).PadLeft(8, '0').Insert(4, " "),
+					_ => value.ToString(), //TODO throw instead?
+				},
+				WatchSize.Word => dispType switch
+				{
+					WatchDisplayType.Signed => unchecked((short) value).ToString(),
+					WatchDisplayType.Unsigned => value.ToString(),
+					WatchDisplayType.Hex => $"{value:X4}",
+					WatchDisplayType.Binary => Convert.ToString(unchecked((ushort) value), toBase: 2).PadLeft(16, '0')
+						.Insert(8, " ").Insert(4, " ").Insert(14, " "),
+					WatchDisplayType.FixedPoint_12_4 => $"{unchecked((short) value) / 16.0:F4}",
+					_ => value.ToString(), //TODO throw instead?
+				},
+				WatchSize.DWord => dispType switch
+				{
+					WatchDisplayType.Signed => unchecked((int) value).ToString(),
+					WatchDisplayType.Unsigned => value.ToString(),
+					WatchDisplayType.Hex => $"{value:X8}",
+					WatchDisplayType.Binary => Convert.ToString(value, toBase: 2).PadLeft(32, '0')
+						.Insert(28, " ").Insert(24, " ").Insert(20, " ").Insert(16, " ").Insert(12, " ").Insert(8, " ").Insert(4, " "),
+					WatchDisplayType.FixedPoint_20_12 => $"{unchecked((int) value) / 4096.0:0.######}",
+					WatchDisplayType.FixedPoint_16_16 => $"{unchecked((int) value) / 65536.0:0.######}",
+					WatchDisplayType.Float => NumberExtensions.ReinterpretAsF32(value).ToString(NumberFormatInfo.InvariantInfo),
+					_ => value.ToString(), //TODO throw instead?
+				},
+				_ => throw new ArgumentOutOfRangeException(paramName: nameof(width), width, message: ERR_MSG_INVALID_WIDTH),
+			};
+
+		public static uint ParseValue(string value, WatchSize width, WatchDisplayType dispType)
+			=> width switch
+			{
+				WatchSize.Byte => dispType switch
+				{
+					WatchDisplayType.Signed => unchecked((byte) sbyte.Parse(value)),
+					WatchDisplayType.Unsigned => byte.Parse(value),
+					WatchDisplayType.Hex => byte.Parse(value, NumberStyles.HexNumber),
+					WatchDisplayType.Binary => Convert.ToByte(value, fromBase: 2),
+					_ => 0, //TODO throw instead?
+				},
+				WatchSize.Word => dispType switch
+				{
+					WatchDisplayType.Signed => unchecked((ushort) short.Parse(value)),
+					WatchDisplayType.Unsigned => ushort.Parse(value),
+					WatchDisplayType.Hex => ushort.Parse(value, NumberStyles.HexNumber),
+					WatchDisplayType.Binary => Convert.ToUInt16(value, fromBase: 2),
+					WatchDisplayType.FixedPoint_12_4 => unchecked((ushort) (16.0 * double.Parse(value, NumberFormatInfo.InvariantInfo))),
+					_ => 0, //TODO throw instead?
+				},
+				WatchSize.DWord => dispType switch
+				{
+					WatchDisplayType.Signed => unchecked((uint) int.Parse(value)),
+					WatchDisplayType.Unsigned => uint.Parse(value),
+					WatchDisplayType.Hex => uint.Parse(value, NumberStyles.HexNumber),
+					WatchDisplayType.Binary => Convert.ToUInt32(value, fromBase: 2),
+					WatchDisplayType.FixedPoint_20_12 => unchecked((uint) (4096.0 * double.Parse(value, NumberFormatInfo.InvariantInfo))),
+					WatchDisplayType.FixedPoint_16_16 => unchecked((uint) (65536.0 * double.Parse(value, NumberFormatInfo.InvariantInfo))),
+					WatchDisplayType.Float => NumberExtensions.ReinterpretAsUInt32(float.Parse(value, NumberFormatInfo.InvariantInfo)),
+					_ => 0, //TODO throw instead?
+				},
+				_ => throw new ArgumentOutOfRangeException(paramName: nameof(width), width, message: ERR_MSG_INVALID_WIDTH),
+			};
+
 		private MemoryDomain _domain;
 		private WatchDisplayType _type;
 
diff --git a/src/BizHawk.Client.Common/tools/Watch/WordWatch.cs b/src/BizHawk.Client.Common/tools/Watch/WordWatch.cs
index aa47d9f889..15f8fb446a 100644
--- a/src/BizHawk.Client.Common/tools/Watch/WordWatch.cs
+++ b/src/BizHawk.Client.Common/tools/Watch/WordWatch.cs
@@ -1,5 +1,5 @@
 using System.Collections.Generic;
-using System.Globalization;
+
 using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.Common
@@ -54,17 +54,7 @@ namespace BizHawk.Client.Common
 		{
 			try
 			{
-				ushort val = Type switch
-				{
-					WatchDisplayType.Unsigned => ushort.Parse(value),
-					WatchDisplayType.Signed => (ushort)short.Parse(value),
-					WatchDisplayType.Hex => ushort.Parse(value, NumberStyles.HexNumber),
-					WatchDisplayType.Binary => Convert.ToUInt16(value, 2),
-					WatchDisplayType.FixedPoint_12_4 => (ushort)(double.Parse(value, NumberFormatInfo.InvariantInfo) * 16.0),
-					_ => 0,
-				};
-
-				PokeWord(val);
+				PokeWord(unchecked((ushort) Watch.ParseValue(value, Size, Type)));
 				return true;
 			}
 			catch
@@ -104,22 +94,7 @@ namespace BizHawk.Client.Common
 
 		// TODO: Implements IFormattable
 		public string FormatValue(ushort val)
-		{
-			return Type switch
-			{
-				_ when !IsValid => "-",
-				WatchDisplayType.Unsigned => val.ToString(),
-				WatchDisplayType.Signed => ((short) val).ToString(), WatchDisplayType.Hex => $"{val:X4}",
-				WatchDisplayType.FixedPoint_12_4 => ((short)val / 16.0).ToString("F4", NumberFormatInfo.InvariantInfo),
-				WatchDisplayType.Binary => Convert
-					.ToString(val, 2)
-					.PadLeft(16, '0')
-					.Insert(8, " ")
-					.Insert(4, " ")
-					.Insert(14, " "),
-				_ => val.ToString(),
-			};
-		}
+			=> IsValid ? Watch.FormatValue(val, Size, Type) : "-";
 
 		public override string Diff => $"{_value - _previous:+#;-#;0}";