diff --git a/README.asciidoc b/README.asciidoc
index 15a58b5f..1d797c0e 100644
--- a/README.asciidoc
+++ b/README.asciidoc
@@ -712,6 +712,7 @@ Some of Kakoune state is available through environment variables:
  * `kak_cursor_line`: line of the end of the main selection
  * `kak_cursor_column`: column of the end of the main selection (in byte)
  * `kak_cursor_char_column`: column of the end of the main selection (in character)
+ * `kak_cursor_byte_offset`: offset of the main selection from the beginning of the buffer (in byte).
  * `kak_window_width`: width of the current kakoune window
  * `kak_window_height`: height of the current kakoune window
  * `kak_hook_param`: filtering text passed to the currently executing hook
diff --git a/src/main.cc b/src/main.cc
index 15c2a867..9a50ec46 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -114,6 +114,11 @@ void register_env_vars()
             [](StringView name, const Context& context) -> String
             { auto coord = context.selections().main().cursor();
               return to_string(context.buffer()[coord.line].char_count_to(coord.column) + 1); }
+        }, {
+            "cursor_byte_offset", false,
+            [](StringView name, const Context& context) -> String
+            { auto cursor = context.selections().main().cursor();
+              return to_string(context.buffer().distance(context.buffer().begin().coord(), cursor)); }
         }, {
             "selection_desc", false,
             [](StringView name, const Context& context)