diff --git a/src/charts/area/stacked.typ b/src/charts/area/stacked.typ
index b6d4e24..528e0e9 100644
--- a/src/charts/area/stacked.typ
+++ b/src/charts/area/stacked.typ
@@ -42,16 +42,18 @@
   ..plot-args
 ) = stacked(
   data.map(d=>{
-    let sum = y-keys.map(k=>d.at(k, default: 0)).sum()
-    for key in y-keys {
-      d.at(key) /= sum
+    let sum = y-keys.map(k=>data.map(d=>d.at(k, default: 0)).sum())
+    for (index, key) in y-keys.enumerate() {
+      d.at(key) /= sum.at(index)
     }
     d
-  }), 
+  }),
   label-key: label-key,
   x-key: x-key,
   y-keys: y-keys,
   area-style: area-style,
   axes: axes,
+  y-tick-step: 0.2,
+  y-format: (it)=>{$#{it*100}%$},
   ..plot-args
 )
\ No newline at end of file
diff --git a/tests/charts/area/stacked/ref/1.png b/tests/charts/area/stacked/ref/1.png
index e9d3f22..546f453 100644
Binary files a/tests/charts/area/stacked/ref/1.png and b/tests/charts/area/stacked/ref/1.png differ
diff --git a/tests/charts/area/stacked100/ref/1.png b/tests/charts/area/stacked100/ref/1.png
index 1a79893..ecb53b0 100644
Binary files a/tests/charts/area/stacked100/ref/1.png and b/tests/charts/area/stacked100/ref/1.png differ
diff --git a/tests/charts/area/stacked100/test.typ b/tests/charts/area/stacked100/test.typ
index 821dba4..c8f5c3e 100644
--- a/tests/charts/area/stacked100/test.typ
+++ b/tests/charts/area/stacked100/test.typ
@@ -6,13 +6,13 @@
   (2.5,  16.3, 17.6, 19.4, 15.3),
   (5,    14.0, 15.3, 13.9, 18.7),
   (7.5,  35.5, 26.5, 29.4, 25.8),
-  (10,   25.0, 20.6, 22.4, 22.0),
-  (12.5, 19.9, 18.2, 19.2, 16.4),
+  // (10,   25.0, 20.6, 22.4, 22.0),
+  // (12.5, 19.9, 18.2, 19.2, 16.4),
 )
 
 #let x-list = (0,  3.3,  6.6, 9.9)
 
-#test-case(cetz-plot.chart.area.stacked(
+#test-case(cetz-plot.chart.area.stacked100(
   size: (10,9),
   x-key: 0,
   y-keys: (1,2,3,4),