diff --git a/tests/benchmark.bench.ts b/tests/benchmark.bench.ts
new file mode 100644
index 0000000..7f16a50
--- /dev/null
+++ b/tests/benchmark.bench.ts
@@ -0,0 +1,68 @@
+import { Q as ourQ } from "../mod.ts";
+
+import JSQ_Qty from "npm:js-quantities@1.8.0";
+import PQM from "npm:pqm@1.0.0";
+
+Deno.bench("Quantity conversions - quantity-math-js", () => {
+    const Q = ourQ;
+    const a = Q`400 g`;
+    const b = Q`50 %`;
+    const c = a.multiply(b); // 200 g
+    const d = c.multiply(Q`50 m/s`); // 10,000 g * m / s (= 10 kg * m / s)
+    const e = d.multiply(Q`0.1 s^-1`); // 1 kg * m / s^2 (= 1 N)
+    const f = e.add(Q`5.5 N`);
+    const g = f.multiply(Q`10`).add(Q`5 N`).add(Q`-20 N`).multiply(Q`2`);
+    const h = g.getSI();
+    if (`${h.magnitude} ${h.units}` !== "100 N") throw new Error(`Got ${h.toString()} unexpectedly.`);
+
+    // And some crazy conversion:
+    const orig = Q`500 uF`;
+    const converted = orig.getWithUnits("h⋅s^3⋅A^2/lb⋅m⋅ft");
+    if (`${converted.magnitude} ${converted.units}` !== "1.920207699666667e-8 h⋅s^3⋅A^2/lb⋅m⋅ft") {
+        throw new Error(`Got ${converted.toString()} unexpectedly.`);
+    }
+});
+
+Deno.bench("Quantity conversions - js-quantities", () => {
+    const Q = JSQ_Qty;
+    const a = Q(`400 g`);
+    const b = Q(`50 %`);
+    //const c = a.mul(b);
+    a.mul(b); // should be 200 g, but with this library it equals "20000 g*%"
+    const c = Q(`200 g`);
+    const d = c.mul(Q(`50 m/s`)); // 10,000 g * m / s (= 10 kg * m / s)
+    const e = d.mul(Q(`0.1 s^-1`)); // 1 kg * m / s^2 (= 1 N)
+    const f = e.add(Q(`5.5 N`));
+    const g = f.mul(Q(`10`)).add(Q(`5 N`)).add(Q(`-20 N`)).mul(Q(`2`));
+    const h = g.toBase();
+    // This library won't simplify to Newtons, since it's technically a derived unit.
+    // So toBase() gives "100 kg*m/s2" not "100 N"
+    if (h.toString() !== "100 kg*m/s2") throw new Error(`Got ${h.toString()} unexpectedly.`);
+
+    // And some crazy conversion:
+    const orig = Q(`500 uF`);
+    const converted = orig.to("h*s^3*A^2/lb*m*ft");
+    if (converted.toString() !== "1.9202076996666664e-8 h*s3*A2/lbs*m*ft") {
+        throw new Error(`Got ${converted.toString()} unexpectedly.`);
+    }
+});
+
+Deno.bench("Quantity conversions - PQM", () => {
+    const Q = PQM.quantity;
+    const a = Q(400, `g`);
+    const b = Q(50, `%`);
+    const c = a.mul(b);
+    const d = c.mul(Q(50, `m/s`)); // 10,000 g * m / s (= 10 kg * m / s)
+    const e = d.mul(Q(0.1, `s^-1`)); // 1 kg * m / s^2 (= 1 N)
+    const f = e.add(Q(5.5, `N`));
+    const g = f.mul(Q(10)).add(Q(5, `N`)).add(Q(-20, `N`)).mul(Q(2));
+    const h = g.inSI();
+    if (h.toString() !== "100,N") throw new Error(`Got ${h.toString()} unexpectedly.`);
+
+    // And some crazy conversion:
+    const orig = Q(500, `uF`);
+    const converted: number = orig.in("hr s^3 A^2/lbm m ft");
+    if (converted.toString() !== "1.920207699666667e-8") {
+        throw new Error(`Got ${converted.toString()} unexpectedly.`);
+    }
+});