diff --git a/src/biopsykit/signals/imu/activity_counts.py b/src/biopsykit/signals/imu/activity_counts.py
index 9790104..778e9b5 100644
--- a/src/biopsykit/signals/imu/activity_counts.py
+++ b/src/biopsykit/signals/imu/activity_counts.py
@@ -134,7 +134,7 @@ def _accumulate_minute_bins(data: np.ndarray) -> np.ndarray:
         n_samples = 10 * 60
         #  Pad data at end to "fill" last bin
         padded_data = np.pad(data, (0, n_samples - len(data) % n_samples), "constant", constant_values=0)
-        return padded_data.reshape((len(padded_data) // n_samples, -1)).mean(axis=1)
+        return padded_data.reshape((len(padded_data) // n_samples, -1)).sum(axis=1)
 
     def calculate(self, data: arr_t) -> arr_t:
         """Calculate Activity Counts from acceleration data.