diff --git a/runtime/reference/cli/coverage.md b/runtime/reference/cli/coverage.md
index ad35c266b..162e47eb4 100644
--- a/runtime/reference/cli/coverage.md
+++ b/runtime/reference/cli/coverage.md
@@ -128,6 +128,26 @@ console.log("This line is ignored");
 console.log("This line is not ignored");
 ```
 
+## Function coverage
+
+The summary table and the HTML report include a **function coverage** column
+alongside the branch and line columns:
+
+```
+----------------------------------
+File         | Branch % | Line % | Function %
+----------------------------------
+main.ts      |   85.7   |  92.3  |   100.0
+util.ts      |   75.0   |  88.5  |    66.7
+----------------------------------
+all files    |   80.0   |  90.5  |    83.3
+----------------------------------
+```
+
+Function coverage measures the percentage of declared functions that were called
+at least once during the test run. The same data is also available in the `lcov`
+output.
+
 ## Output Formats
 
 By default we support Deno's own coverage format - but you can also output