diff --git a/test/percent-sizing.test.ts b/test/percent-sizing.test.ts
new file mode 100644
index 0000000..6e862aa
--- /dev/null
+++ b/test/percent-sizing.test.ts
@@ -0,0 +1,55 @@
+import { beforeEach, describe, expect, it } from "./suite.ts";
+import { createTerm, type Term } from "../term.ts";
+import { close, fit, fixed, open, percent, text } from "../ops.ts";
+
+describe("percent min/max sizing", () => {
+  let term: Term;
+
+  beforeEach(async () => {
+    term = await createTerm({ width: 20, height: 12 });
+  });
+
+  it("fit(min = percent(0.5)) grows a short child to 50% of the parent", () => {
+    let r = term.render([
+      open("parent", { layout: { height: fixed(12), direction: "ttb" } }),
+      open("child", {
+        layout: { height: fit(percent(0.5) as unknown as number) },
+      }),
+      text("A"),
+      close(),
+      close(),
+    ]);
+    // pins: a 1-line fit child is floored to 50% of the 12-row parent
+    expect(r.info.get("child")!.bounds.height).toBe(6);
+  });
+
+  it("fit(min = percent(0.5)) is a floor, not a fixed cap", () => {
+    let r = term.render([
+      open("parent", { layout: { height: fixed(12), direction: "ttb" } }),
+      open("child", {
+        layout: { height: fit(percent(0.5) as unknown as number) },
+      }),
+      text("A\nA\nA\nA\nA\nA\nA\nA"),
+      close(),
+      close(),
+    ]);
+    // pins: content taller than 50% is allowed past the floor, not pinned to 6
+    expect(r.info.get("child")!.bounds.height).toBe(8);
+  });
+
+  it("fit(0, max = percent(0.5)) clamps a tall child down to 50%", () => {
+    let r = term.render([
+      open("parent", { layout: { height: fixed(12), direction: "ttb" } }),
+      open("child", {
+        layout: { height: fit(0, percent(0.5) as unknown as number) },
+      }),
+      open("inner", { layout: { height: fixed(12) } }),
+      text("A"),
+      close(),
+      close(),
+      close(),
+    ]);
+    // pins: a 12-row inner is clamped down to 50% (6) of the parent
+    expect(r.info.get("child")!.bounds.height).toBe(6);
+  });
+});