diff --git a/src/pages/product/manage.vue b/src/pages/product/manage.vue
index b36284c..d119da1 100644
--- a/src/pages/product/manage.vue
+++ b/src/pages/product/manage.vue
@@ -65,17 +65,17 @@
               </view>
             </picker>
           </view>
-          <view class="form-row">
+          <view class="form-row size-row">
             <view class="form-item half">
-              <text class="label">长度</text>
-              <input class="input" type="digit" v-model="form.length" placeholder="非必须" />
+              <text class="label">长度(mm)</text>
+              <input class="input" type="digit" v-model="form.length" placeholder="非必须" maxlength="5" />
             </view>
             <view class="form-item half">
-              <text class="label">宽度</text>
-              <input class="input" type="digit" v-model="form.width" placeholder="非必须" />
+              <text class="label">宽度(mm)</text>
+              <input class="input" type="digit" v-model="form.width" placeholder="非必须" maxlength="5" />
             </view>
             <view class="form-item half">
-              <text class="label">面积</text>
+              <text class="label">面积(m²)</text>
               <input class="input" type="digit" v-model="form.area" placeholder="自动计算" disabled />
             </view>
           </view>
@@ -151,9 +151,9 @@ export default {
     computedArea() {
       const l = parseFloat(this.form.length)
       const w = parseFloat(this.form.width)
-      // 长度(cm) × 宽度(cm) ÷ 10000 = 面积(m²)
+      // 长度(mm) × 宽度(mm) ÷ 1000000 = 面积(m²)
       if (!isNaN(l) && !isNaN(w) && l > 0 && w > 0) {
-        return (l * w / 10000).toFixed(2)
+        return (l * w / 1000000).toFixed(4)
       }
       return ''
     }