diff --git a/transformer_thermal_model/schemas/thermal_model/input_profile.py b/transformer_thermal_model/schemas/thermal_model/input_profile.py
index 82ae235..6df6e78 100644
--- a/transformer_thermal_model/schemas/thermal_model/input_profile.py
+++ b/transformer_thermal_model/schemas/thermal_model/input_profile.py
@@ -36,7 +36,7 @@ def time_step(self) -> np.ndarray:
         """
         # Calculate time steps in minutes
         time_deltas = (
-            np.diff(self.datetime_index, prepend=self.datetime_index[0]).astype("timedelta64[s]").astype(float) / 60
+            np.diff(self.datetime_index, prepend=self.datetime_index[0]).astype("timedelta64[m]").astype(float)
         )
         return time_deltas