diff --git a/dataprocessing/timeseries.py b/dataprocessing/timeseries.py
index 3acd3b5a87840499b7cc9970144402123362a30b..7ab5234991a70dff9e8016fea38dd23c9be63450 100644
--- a/dataprocessing/timeseries.py
+++ b/dataprocessing/timeseries.py
@@ -37,6 +37,12 @@ class TimeSeries:
         ts_phase = TimeSeries(name, self.time, phase_values)
         return ts_phase
 
+    @staticmethod
+    def rmse(ts1, ts2):
+        """ Calculate root mean square error between two time series
+        """
+        return np.sqrt((TimeSeries.diff('diff', ts1, ts2).values ** 2).mean())
+
     @staticmethod
     def diff(name, ts1, ts2):
         """Returns difference between values of two Timeseries objects.