diff --git a/vllm/multimodal/processing.py b/vllm/multimodal/processing.py
index 0390773783961..f337bc9b0f7ba 100644
--- a/vllm/multimodal/processing.py
+++ b/vllm/multimodal/processing.py
@@ -1389,6 +1389,22 @@ class BaseMultiModalProcessor(ABC, Generic[_I]):
         """Given the HF-processed data, output the metadata of each field."""
         raise NotImplementedError
 
+    @abstractmethod
+    def get_num_mm_encoder_tokens(
+        self,
+        num_image_tokens: int,
+    ) -> int:
+        """Given the number of image tokens, output the number of multi-modal encoder tokens"""
+        raise NotImplementedError
+
+    @abstractmethod
+    def get_num_mm_connector_tokens(
+        self,
+        num_vision_tokens: int,
+    ) -> int:
+        """Given the number of vision tokens, output the number of multi-modal connector tokens"""
+        raise NotImplementedError
+
     @abstractmethod
     def _get_prompt_updates(
         self,