diff --git a/src/experimental/_impl/_sum_impl.scad b/src/experimental/_impl/_sum_impl.scad
new file mode 100644
index 00000000..2c2bc47b
--- /dev/null
+++ b/src/experimental/_impl/_sum_impl.scad
@@ -0,0 +1,2 @@
+function _sum_impl(lt, leng, i = 0) =
+    i == leng - 1 ? lt[i] : (lt[i] + _sum_impl(lt, leng, i + 1));
diff --git a/src/experimental/sum.scad b/src/experimental/sum.scad
new file mode 100644
index 00000000..14d62e5f
--- /dev/null
+++ b/src/experimental/sum.scad
@@ -0,0 +1,3 @@
+use <experimental/_impl/_sum_impl.scad>;
+
+function sum(lt) = _sum_impl(lt, len(lt));
\ No newline at end of file