diff --git a/perception/image_projection_based_fusion/CMakeLists.txt b/perception/image_projection_based_fusion/CMakeLists.txt
index 7baed86088811..825c4888ac7ea 100644
--- a/perception/image_projection_based_fusion/CMakeLists.txt
+++ b/perception/image_projection_based_fusion/CMakeLists.txt
@@ -162,6 +162,9 @@ endif()
 
 if(BUILD_TESTING)
   find_package(ament_cmake_gtest REQUIRED)
+  ament_auto_add_gtest(test_calc_iou_functions
+    test/test_calc_iou_functions.cpp
+  )
   ament_auto_add_gtest(test_utils
     test/test_utils.cpp
   )
diff --git a/perception/image_projection_based_fusion/test/test_calc_iou_functions.cpp b/perception/image_projection_based_fusion/test/test_calc_iou_functions.cpp
new file mode 100644
index 0000000000000..1cddef44c0bac
--- /dev/null
+++ b/perception/image_projection_based_fusion/test/test_calc_iou_functions.cpp
@@ -0,0 +1,122 @@
+// Copyright 2024 TIER IV, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "image_projection_based_fusion/utils/geometry.hpp"
+
+#include <gtest/gtest.h>
+
+using image_projection_based_fusion::calcIoU;
+using image_projection_based_fusion::calcIoUX;
+using image_projection_based_fusion::calcIoUY;
+
+TEST(GeometryTest, CalcIoU)
+{
+  sensor_msgs::msg::RegionOfInterest roi1, roi2;
+
+  // Overlapping ROIs
+  roi1.x_offset = 0;
+  roi1.y_offset = 0;
+  roi1.width = 4;
+  roi1.height = 4;
+
+  roi2.x_offset = 2;
+  roi2.y_offset = 2;
+  roi2.width = 4;
+  roi2.height = 4;
+
+  double iou = calcIoU(roi1, roi2);
+  EXPECT_NEAR(iou, 1.0 / 7.0, 1e-6);
+
+  // Non-overlapping ROIs
+  roi2.x_offset = 5;
+  roi2.y_offset = 5;
+
+  iou = calcIoU(roi1, roi2);
+  EXPECT_EQ(iou, 0.0);
+
+  // Zero area ROI
+  roi1.width = 0;
+  roi1.height = 0;
+
+  iou = calcIoU(roi1, roi2);
+  EXPECT_EQ(iou, 0.0);
+}
+
+TEST(GeometryTest, CalcIoUX)
+{
+  sensor_msgs::msg::RegionOfInterest roi1, roi2;
+
+  // Overlapping ROIs on x-axis
+  roi1.x_offset = 0;
+  roi1.y_offset = 0;
+  roi1.width = 4;
+  roi1.height = 4;
+
+  roi2.x_offset = 2;
+  roi2.y_offset = 0;
+  roi2.width = 4;
+  roi2.height = 4;
+
+  double iou_x = calcIoUX(roi1, roi2);
+  EXPECT_NEAR(iou_x, 2.0 / 6.0, 1e-6);
+
+  // Non-overlapping ROIs on x-axis
+  roi2.x_offset = 5;
+
+  iou_x = calcIoUX(roi1, roi2);
+  EXPECT_EQ(iou_x, 0.0);
+
+  // Zero width ROI
+  roi1.width = 0;
+
+  iou_x = calcIoUX(roi1, roi2);
+  EXPECT_EQ(iou_x, 0.0);
+}
+
+TEST(GeometryTest, CalcIoUY)
+{
+  sensor_msgs::msg::RegionOfInterest roi1, roi2;
+
+  // Overlapping ROIs on y-axis
+  roi1.x_offset = 0;
+  roi1.y_offset = 0;
+  roi1.width = 4;
+  roi1.height = 4;
+
+  roi2.x_offset = 0;
+  roi2.y_offset = 2;
+  roi2.width = 4;
+  roi2.height = 4;
+
+  double iou_y = calcIoUY(roi1, roi2);
+  EXPECT_NEAR(iou_y, 2.0 / 6.0, 1e-6);
+
+  // Non-overlapping ROIs on y-axis
+  roi2.y_offset = 5;
+
+  iou_y = calcIoUY(roi1, roi2);
+  EXPECT_EQ(iou_y, 0.0);
+
+  // Zero height ROI
+  roi1.height = 0;
+
+  iou_y = calcIoUY(roi1, roi2);
+  EXPECT_EQ(iou_y, 0.0);
+}
+
+int main(int argc, char ** argv)
+{
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}