diff --git a/css/css-writing-modes/forms/checkbox-switch-input-computed-style.tentative.html b/css/css-writing-modes/forms/checkbox-switch-input-computed-style.tentative.html
new file mode 100644
index 00000000000000..f8d8d6fca28c8f
--- /dev/null
+++ b/css/css-writing-modes/forms/checkbox-switch-input-computed-style.tentative.html
@@ -0,0 +1,37 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Switch input writing mode computed style</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<input type=checkbox switch id=horizontal-input style="writing-mode: horizontal-tb">
+<input type=checkbox switch id=vertical-lr-input style="writing-mode: vertical-lr">
+<input type=checkbox switch id=vertical-rl-input style="writing-mode: vertical-rl">
+
+<script>
+for (const element of document.querySelectorAll("[id^='horizontal-']")) {
+    test(() => {
+        const style = getComputedStyle(element);
+        const blockSize = parseInt(style.blockSize, 10);
+        const inlineSize = parseInt(style.inlineSize, 10);
+        assert_not_equals(blockSize, 0);
+        assert_not_equals(inlineSize, 0);
+        assert_greater_than(inlineSize, blockSize);
+        assert_equals(style.blockSize, style.height);
+        assert_equals(style.inlineSize, style.width);
+    }, `${element.id} block size should match height and inline size should match width`);
+}
+
+for (const element of document.querySelectorAll("[id^='vertical-']")) {
+    test(() => {
+        const style = getComputedStyle(element);
+        const blockSize = parseInt(style.blockSize, 10);
+        const inlineSize = parseInt(style.inlineSize, 10);
+        assert_not_equals(blockSize, 0);
+        assert_not_equals(inlineSize, 0);
+        assert_greater_than(inlineSize, blockSize);
+        assert_equals(style.blockSize, style.width);
+        assert_equals(style.inlineSize, style.height);
+    }, `${element.id} block size should match width and inline size should match height`);
+}
+</script>
