diff --git a/wpimath/src/main/java/edu/wpi/first/math/geometry/Rotation3d.java b/wpimath/src/main/java/edu/wpi/first/math/geometry/Rotation3d.java
index e7bbfa92b6..bd39ecac6f 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/geometry/Rotation3d.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/geometry/Rotation3d.java
@@ -45,6 +45,10 @@ public class Rotation3d implements Interpolatable<Rotation3d> {
    * <p>Extrinsic rotations occur in that order around the axes in the fixed global frame rather
    * than the body frame.
    *
+   * <p>Angles are measured counterclockwise with the rotation axis pointing "out of the page". If
+   * you point your right thumb along the positive axis direction, your fingers curl in the
+   * direction of positive rotation.
+   *
    * @param roll The counterclockwise rotation angle around the X axis (roll) in radians.
    * @param pitch The counterclockwise rotation angle around the Y axis (pitch) in radians.
    * @param yaw The counterclockwise rotation angle around the Z axis (yaw) in radians.
diff --git a/wpimath/src/main/native/include/frc/geometry/Rotation3d.h b/wpimath/src/main/native/include/frc/geometry/Rotation3d.h
index a2bffbbdb9..39674733d2 100644
--- a/wpimath/src/main/native/include/frc/geometry/Rotation3d.h
+++ b/wpimath/src/main/native/include/frc/geometry/Rotation3d.h
@@ -40,6 +40,10 @@ class WPILIB_DLLEXPORT Rotation3d {
    * Extrinsic rotations occur in that order around the axes in the fixed global
    * frame rather than the body frame.
    *
+   * Angles are measured counterclockwise with the rotation axis pointing "out
+   * of the page". If you point your right thumb along the positive axis
+   * direction, your fingers curl in the direction of positive rotation.
+   *
    * @param roll The counterclockwise rotation angle around the X axis (roll).
    * @param pitch The counterclockwise rotation angle around the Y axis (pitch).
    * @param yaw The counterclockwise rotation angle around the Z axis (yaw).