diff --git a/pyanaconda/modules/payloads/source/live_os/initialization.py b/pyanaconda/modules/payloads/source/live_os/initialization.py
index ecb225c7288..d3a1dde1699 100644
--- a/pyanaconda/modules/payloads/source/live_os/initialization.py
+++ b/pyanaconda/modules/payloads/source/live_os/initialization.py
@@ -108,11 +108,37 @@ def run(self):
         return SetupLiveOSResult(required_space=required_space)
 
     def _calculate_required_space(self):
-        """Calculate size of the live image image."""
-        source = os.statvfs(self._target_mount)
-        required_space = source.f_frsize * (source.f_blocks - source.f_bfree)
-        log.debug("Required space: %s", Size(required_space))
-        return required_space
+        """
+        Calculate the disk space required for the live OS by summing up
+        the size of relevant directories using 'du -s'.
+        """
+        exclude_patterns = [
+            "/dev/",
+            "/proc/",
+            "/tmp/*",
+            "/sys/",
+            "/run/",
+            "/boot/*rescue*",
+            "/boot/loader/",
+            "/boot/efi/loader/",
+            "/etc/machine-id",
+            "/etc/machine-info"
+        ]
+
+        # Build the `du` command
+        du_cmd_args = ["--bytes", "--summarize", self._target_mount]
+        for pattern in exclude_patterns:
+            du_cmd_args.extend(["--exclude", f"{self._target_mount}{pattern}"])
+
+        try:
+            # Execute the `du` command
+            result = execWithCapture("du", du_cmd_args)
+            # Parse the output for the total size
+            required_space = result.split()[0]  # First column is the total
+            log.debug("Required space: %s", Size(required_space))
+            return int(required_space)
+        except (OSError, FileNotFoundError) as e:
+            raise SourceSetupError(str(e)) from e
 
     @property
     def name(self):
diff --git a/tests/unit_tests/pyanaconda_tests/modules/payloads/source/test_source_live_os.py b/tests/unit_tests/pyanaconda_tests/modules/payloads/source/test_source_live_os.py
index 63a7ffbe9fe..77ad4c74ea1 100644
--- a/tests/unit_tests/pyanaconda_tests/modules/payloads/source/test_source_live_os.py
+++ b/tests/unit_tests/pyanaconda_tests/modules/payloads/source/test_source_live_os.py
@@ -128,10 +128,10 @@ def test_repr(self):
 
 class LiveOSSourceTasksTestCase(unittest.TestCase):
     """Test the tasks of the Live OS source."""
-    @patch("pyanaconda.modules.payloads.source.live_os.initialization.os.statvfs")
-    def test_live_os_image_size(self, statvfs):
+    @patch("pyanaconda.modules.payloads.source.live_os.initialization.execWithCapture")
+    def test_live_os_image_size(self, exec_mock):
         """Test Live OS image size calculation."""
-        statvfs.return_value = Mock(f_frsize=512, f_blocks=100, f_bfree=42)
+        exec_mock.return_value = "29696      /path/to/base/image/"
 
         task = SetUpLiveOSSourceTask(
                 "/path/to/base/image",