diff --git a/masque/__init__.py b/masque/__init__.py
index 93eabdc..dbd0670 100644
--- a/masque/__init__.py
+++ b/masque/__init__.py
@@ -83,6 +83,8 @@ from .builder import (
 from .utils import (
     ports2data as ports2data,
     oneshot as oneshot,
+    R90 as R90,
+    R180 as R180,
     )
 
 
diff --git a/masque/utils/__init__.py b/masque/utils/__init__.py
index 11391a5..f33142f 100644
--- a/masque/utils/__init__.py
+++ b/masque/utils/__init__.py
@@ -25,6 +25,8 @@ from .transform import (
     normalize_mirror as normalize_mirror,
     rotate_offsets_around as rotate_offsets_around,
     apply_transforms as apply_transforms,
+    R90 as R90,
+    R180 as R180,
     )
 from .comparisons import (
     annotation2key as annotation2key,
diff --git a/masque/utils/transform.py b/masque/utils/transform.py
index e2ea9aa..dfb6492 100644
--- a/masque/utils/transform.py
+++ b/masque/utils/transform.py
@@ -9,6 +9,11 @@ from numpy.typing import NDArray, ArrayLike
 from numpy import pi
 
 
+# Constants for shorthand rotations
+R90 = pi / 2
+R180 = pi
+
+
 @lru_cache
 def rotation_matrix_2d(theta: float) -> NDArray[numpy.float64]:
     """