diff --git a/python/stempy/image/__init__.py b/python/stempy/image/__init__.py
index dee8d95d..94db98a0 100644
--- a/python/stempy/image/__init__.py
+++ b/python/stempy/image/__init__.py
@@ -404,7 +404,7 @@ def com_v1_kernel(
     position_indices: np.ndarray,
     scan_shape: Tuple[int, int],
     frame_shape: Tuple[int, int],
-    crop_to: Union[Tuple[int, int], None] = None,
+    crop_to: Union[int, None] = None,
     init_center: Union[Tuple[int, int], None] = None,
     replace_nans: bool = True,
 ) -> np.ndarray:
@@ -432,12 +432,8 @@ def com_v1_kernel(
     # Cropping
     if crop_to is not None:
         if init_center is not None:
-            xmin = init_center[0] - crop_to[0]
-            xmax = init_center[0] + crop_to[0]
-            ymin = init_center[1] - crop_to[1]
-            ymax = init_center[1] + crop_to[1]
-
-            mask = (x > xmin) & (x <= xmax) & (y > ymin) & (y <= ymax)
+            r = np.sqrt((x - init_center[0])**2 + (y - init_center[1])**2)
+            mask = (r < crop_to)
             position_indices = position_indices[mask]
             x = x[mask]
             y = y[mask]
@@ -454,13 +450,8 @@ def com_v1_kernel(
 
             event_center_x = centers_x[position_indices]
             event_center_y = centers_y[position_indices]
-
-            mask = (
-                (x > event_center_x - crop_to[0])
-                & (x <= event_center_x + crop_to[0])
-                & (y > event_center_y - crop_to[1])
-                & (y <= event_center_y + crop_to[1])
-            )
+            r = np.sqrt((x - event_center_x)**2 + (y - event_center_y)**2)
+            mask = (r < crop_to)
             position_indices = position_indices[mask]
             x = x[mask]
             y = y[mask]
@@ -552,8 +543,8 @@ def _com_sparse_v0(array, crop_to=None, init_center=None, replace_nans=True):
             
             if crop_to is not None:
                 # Crop around the initial center
-                keep = (x > comx0 - crop_to[0]) & (x <= comx0 + crop_to[0]) & (y > comy0 - crop_to[1]) & (
-                        y <= comy0 + crop_to[1])
+                r = np.sqrt((x - comx0)**2 + (y - comy0)**2)
+                keep = (r < crop_to)
                 x = x[keep]
                 y = y[keep]
                 mm = len(x)
@@ -594,9 +585,9 @@ def com_sparse(
 
     :param array: A SparseArray of the electron counted data
     :type array: stempy.io.SparseArray
-    :param crop_to: optional; The size of the region to crop around initial full frame COM for improved COM near
+    :param crop_to: optional; The radius from the center to crop around initial full frame COM for improved COM near
                     the zero beam
-    :type crop_to: tuple of ints of length 2
+    :type crop_to: int
     :param init_center: optional; The initial center to use before cropping. If this is not set then cropping will be applied around
                         the center of mass of the each full frame.
     :type init_center: tuple of ints of length 2
diff --git a/tests/test_image.py b/tests/test_image.py
index a964c41c..731836a4 100644
--- a/tests/test_image.py
+++ b/tests/test_image.py
@@ -58,12 +58,12 @@ def test_com_sparse_parameters(simulate_sparse_array, version):
     assert round(com0[0,].mean()) == 30
     
     # Test crop_to input. Initial COM should be full frame COM
-    com1 = com_sparse(sp, crop_to=(10, 10), version=version)
+    com1 = com_sparse(sp, crop_to=10, version=version)
     assert round(com1[0,].mean()) == 30
     
     # Test crop_to and init_center input.
     # No counts will be in the center so all positions will be np.nan
-    com2 = com_sparse(sp, crop_to=(10, 10), init_center=(1, 1), version=version)
+    com2 = com_sparse(sp, crop_to=10, init_center=(1, 1), version=version)
     assert np.isnan(com2[0,0,0])
 
 
@@ -75,17 +75,17 @@ def test_com_sparse_version_comparison(sparse_array_small):
         {"crop_to": None, "init_center": None, "replace_nans": True},
         {"crop_to": None, "init_center": None, "replace_nans": False},
         {
-            "crop_to": (frame_x // 2, frame_y // 2),
+            "crop_to": frame_x // 2,
             "init_center": None,
             "replace_nans": True,
         },
         {
-            "crop_to": (frame_x // 2, frame_y // 2),
+            "crop_to": frame_x // 2,
             "init_center": (frame_x // 2, frame_y // 2),
             "replace_nans": True,
         },
         {
-            "crop_to": (frame_x // 2, frame_y // 2),
+            "crop_to": frame_x // 2,
             "init_center": (frame_x // 2, frame_y // 2),
             "replace_nans": False,
         },