diff --git a/rsrcfork/__main__.py b/rsrcfork/__main__.py
index b93b91f..0af37b4 100644
--- a/rsrcfork/__main__.py
+++ b/rsrcfork/__main__.py
@@ -197,13 +197,13 @@ def _describe_resource(res: api.Resource, *, include_type: bool, decompress: boo
 	
 	if decompress and api.ResourceAttrs.resCompressed in res.attributes:
 		try:
-			res.data
+			res.compressed_info
 		except compress.DecompressError:
-			length_desc = f"decompression failed ({len(res.data_raw)} bytes compressed)"
+			length_desc = f"decompression failed ({res.length_raw} bytes compressed)"
 		else:
-			length_desc = f"{len(res.data)} bytes ({len(res.data_raw)} bytes compressed)"
+			length_desc = f"{res.length} bytes ({res.length_raw} bytes compressed)"
 	else:
-		length_desc = f"{len(res.data_raw)} bytes"
+		length_desc = f"{res.length_raw} bytes"
 	content_desc_parts.append(length_desc)
 	
 	attrs = _decompose_flags(res.attributes)
diff --git a/rsrcfork/api.py b/rsrcfork/api.py
index 9ea6abe..b1819f3 100644
--- a/rsrcfork/api.py
+++ b/rsrcfork/api.py
@@ -154,6 +154,27 @@ class Resource(object):
 		else:
 			return None
 	
+	@property
+	def length_raw(self) -> int:
+		"""The length of the raw resource data, which may be compressed.
+		
+		Accessing this attribute may be faster than computing len(self.data_raw) manually.
+		"""
+		
+		return len(self.data_raw)
+	
+	@property
+	def length(self) -> int:
+		"""The length of the resource data. If the resource data is compressed, this is the length of the data after decompression.
+		
+		Accessing this attribute may be faster than computing len(self.data) manually.
+		"""
+		
+		if ResourceAttrs.resCompressed in self.attributes:
+			return self.compressed_info.decompressed_length
+		else:
+			return self.length_raw
+	
 	@property
 	def data(self) -> bytes:
 		"""The resource data, decompressed if necessary.