diff --git a/VectoCore/Utils/DoubleExtensionMethods.cs b/VectoCore/Utils/DoubleExtensionMethods.cs
index bc3c762ffe1b6050d7246aaa2431230c547c23db..4ff037e5621ca1d99b590f88f45a6c4978aedb5e 100644
--- a/VectoCore/Utils/DoubleExtensionMethods.cs
+++ b/VectoCore/Utils/DoubleExtensionMethods.cs
@@ -98,7 +98,8 @@ namespace TUGraz.VectoCore.Utils
 		/// <returns></returns>
 		public static PerSecond RPMtoRad(this double self)
 		{
-			return self.SI().Rounds.Per.Minute.ConvertTo().Radian.Per.Second.Cast<PerSecond>();
+			return SI<PerSecond>(self * 2 * Math.PI / 60.0);
+			//self.SI().Rounds.Per.Minute.ConvertTo().Radian.Per.Second.Cast<PerSecond>();
 		}
 
 		public static MeterPerSecond KMPHtoMeterPerSecond(this double self)
diff --git a/VectoCore/Utils/IntExtensionMethods.cs b/VectoCore/Utils/IntExtensionMethods.cs
index ed3e3109766984f6083baccc4eb3cf9a4cff239a..902593ee8b40bd23b6e88f4d5ab8e31707ccb1ac 100644
--- a/VectoCore/Utils/IntExtensionMethods.cs
+++ b/VectoCore/Utils/IntExtensionMethods.cs
@@ -12,12 +12,14 @@ namespace TUGraz.VectoCore.Utils
 		/// <returns></returns>
 		public static PerSecond RPMtoRad(this int d)
 		{
-			return d.SI().Rounds.Per.Minute.ConvertTo().Radian.Per.Second.Cast<PerSecond>();
+			return (d * 2.0 * Math.PI / 60.0).SI<PerSecond>();
+			//d.SI().Rounds.Per.Minute.ConvertTo().Radian.Per.Second.Cast<PerSecond>();
 		}
 
 		public static MeterPerSecond KMPHtoMeterPerSecond(this int d)
 		{
-			return d.SI().Kilo.Meter.Per.Hour.Cast<MeterPerSecond>();
+			return (d / 3.6).SI<MeterPerSecond>();
+			//d.SI().Kilo.Meter.Per.Hour.Cast<MeterPerSecond>();
 		}