diff --git a/lua/util.lua b/lua/util.lua
index f103d40..7513b5b 100644
--- a/lua/util.lua
+++ b/lua/util.lua
@@ -80,13 +80,11 @@ function Util.format(opts)
         )[1]
     end
 
-    local function get_byte_offset(buf, row, col)
-        local lines = vim.api.nvim_buf_get_text(buf, 0, 0, row - 1, col - 1, {})
-        return #table.concat(lines, "\n")
-    end
-
-    local byte_start = get_byte_offset(opts.buf, row_start, col_start)
-    local byte_end = get_byte_offset(opts.buf, row_end, col_end) + 1
+    local byte_start = vim.api.nvim_buf_get_offset(opts.buf, row_start - 1)
+        + col_start
+        - 1
+    local byte_end = vim.api.nvim_buf_get_offset(opts.buf, row_end - 1)
+        + col_end
 
     local input
     if is_visual and opts.only_selection then