diff --git a/src/type/unit/Unit.js b/src/type/unit/Unit.js
index 87498385b0..bd80689dcf 100644
--- a/src/type/unit/Unit.js
+++ b/src/type/unit/Unit.js
@@ -1837,9 +1837,9 @@ export const createUnitClass = /* #__PURE__ */ factory(name, dependencies, ({
       name: 'acre',
       base: BASE_UNITS.SURFACE,
       prefixes: PREFIXES.NONE,
-      value: 4046.86,
+      value: 4046.8564224,
       offset: 0
-    }, // 4046.86 m2
+    }, // 4046.8564224 m2 (4840 sqyd)
     hectare: {
       name: 'hectare',
       base: BASE_UNITS.SURFACE,
diff --git a/test/unit-tests/type/unit/Unit.test.js b/test/unit-tests/type/unit/Unit.test.js
index b8a2fe96a5..db029b4c77 100644
--- a/test/unit-tests/type/unit/Unit.test.js
+++ b/test/unit-tests/type/unit/Unit.test.js
@@ -1234,6 +1234,11 @@ describe('Unit', function () {
       assert.strictEqual(new Unit(1, 'kilogramforce').equals(new Unit(1, 'kgf')), true)
     })
 
+    it('should define acre exactly as 4840 sqyd', function () {
+      assert.strictEqual(new Unit(1, 'acre').equals(new Unit(4840, 'sqyd')), true)
+      assert.strictEqual(new Unit(1, 'acre').equals(new Unit(43560, 'sqft')), true)
+    })
+
     it("For each built-in unit, 'name' should match key", function () {
       for (const key in Unit.UNITS) {
         if (hasOwnProperty(Unit.UNITS, key)) {