diff --git a/backend/scanner.js b/backend/scanner.js
index 52173fe..a58969e 100644
--- a/backend/scanner.js
+++ b/backend/scanner.js
@@ -65,7 +65,8 @@ function readJson(file) {
 }
 
 function fmtMb(bytes) {
-  return Number((bytes / 1024 / 1024).toFixed(1))
+  // 保留到 KB 级精度：toFixed(1) 会把 <0.05MB 的轻量包（几 KB~几十 KB）截成 0
+  return Math.round((bytes / 1024 / 1024) * 1024) / 1024
 }
 
 // 目录名 → 包名（支持 scoped：@scope/name）
diff --git a/frontend/src/components/CleanDialog.vue b/frontend/src/components/CleanDialog.vue
index 607730f..8ce3120 100644
--- a/frontend/src/components/CleanDialog.vue
+++ b/frontend/src/components/CleanDialog.vue
@@ -1,6 +1,6 @@
 <script setup>
 import { ref, computed, watch } from 'vue'
-import { useStore } from '../store'
+import { useStore, fmtSize } from '../store'
 import api from '../api'
 
 const props = defineProps({
@@ -81,7 +81,7 @@ async function confirm() {
         <div class="cd-body">
           <div class="cd-pkg">
             <span class="cd-pkg-name">{{ pkg.name }}</span>
-            <span class="cd-pkg-meta">当前 {{ pkg.versions }} 个版本 · {{ pkg.size }} MB</span>
+            <span class="cd-pkg-meta">当前 {{ pkg.versions }} 个版本 · {{ fmtSize(pkg.size) }}</span>
           </div>
 
           <div class="cd-row">
@@ -105,7 +105,7 @@ async function confirm() {
         </div>
 
         <div class="cd-foot">
-          <span class="cd-freed">预计释放 {{ freedSpace.toFixed(1) }} MB</span>
+          <span class="cd-freed">预计释放 {{ fmtSize(freedSpace) }}</span>
           <button class="btn unignore" @click="emit('close')">取消</button>
           <button class="btn clean" :class="{ disabled: !toDelete.length }" :disabled="cleaning || !toDelete.length" @click="confirm">
             {{ cleaning ? '清理中…' : `确认清理 ${toDelete.length} 个` }}
diff --git a/frontend/src/components/PackageCard.vue b/frontend/src/components/PackageCard.vue
index 492c083..4f01c58 100644
--- a/frontend/src/components/PackageCard.vue
+++ b/frontend/src/components/PackageCard.vue
@@ -1,6 +1,7 @@
 <script setup>
 import StatusTag from './StatusTag.vue'
 import PkgLogo from './PkgLogo.vue'
+import { fmtSize } from '../store'
 
 defineProps({
   pkg: { type: Object, required: true },
@@ -41,7 +42,7 @@ function splitName(name) {
         <div class="m-l">版本数</div>
       </div>
       <div class="m-item">
-        <div class="m-v">{{ pkg.size }} MB</div>
+        <div class="m-v">{{ fmtSize(pkg.size) }}</div>
         <div class="m-l">占用空间</div>
       </div>
     </div>
diff --git a/frontend/src/components/PackageDrawer.vue b/frontend/src/components/PackageDrawer.vue
index f911958..26b9760 100644
--- a/frontend/src/components/PackageDrawer.vue
+++ b/frontend/src/components/PackageDrawer.vue
@@ -3,6 +3,7 @@ import { ref, computed, watch } from 'vue'
 import StatusTag from './StatusTag.vue'
 import PkgLogo from './PkgLogo.vue'
 import api from '../api'
+import { fmtSize } from '../store'
 
 const props = defineProps({
   visible: Boolean,
@@ -90,7 +91,7 @@ function delVersion(v) {
             </div>
             <div class="kv">
               <div class="k">占用空间</div>
-              <div class="v">{{ pkg.size }} MB</div>
+              <div class="v">{{ fmtSize(pkg.size) }}</div>
             </div>
             <div class="kv">
               <div class="k">最近更新</div>
@@ -127,7 +128,7 @@ function delVersion(v) {
             </div>
             <div v-for="v in verList" :key="v.version" class="ver-row">
               <span class="ver-no">{{ v.version }}</span>
-              <span class="ver-size">{{ v.size }} MB</span>
+              <span class="ver-size">{{ fmtSize(v.size) }}</span>
               <span class="ver-date">{{ fmtDate(v.date) }}</span>
               <button class="del-btn" title="删除此版本" @click="delVersion(v)">🗑</button>
             </div>
diff --git a/frontend/src/components/Top30Panel.vue b/frontend/src/components/Top30Panel.vue
index 5c08d7b..3786310 100644
--- a/frontend/src/components/Top30Panel.vue
+++ b/frontend/src/components/Top30Panel.vue
@@ -1,16 +1,13 @@
 <script setup>
 // 排行 Top 30：有访问统计按热度，否则降级为缓存占用（真实环境无访问统计）
 import PkgLogo from './PkgLogo.vue'
+import { fmtSize } from '../store'
 const props = defineProps({
   top30: { type: Array, default: () => [] },
   top30By: { type: String, default: 'visits' },
 })
 const emit = defineEmits(['open'])
 const isVisits = props.top30By === 'visits'
-function fmtSize(mb) {
-  if (mb >= 1024) return `${(mb / 1024).toFixed(1)} GB`
-  return `${mb.toFixed(1)} MB`
-}
 </script>
 
 <template>
diff --git a/frontend/src/store/index.js b/frontend/src/store/index.js
index da9dd69..f8e9204 100644
--- a/frontend/src/store/index.js
+++ b/frontend/src/store/index.js
@@ -64,16 +64,22 @@ const stats = computed(() => {
 
 function fmtSize(mb) {
   if (mb >= 1024) return `${(mb / 1024).toFixed(1)} GB`
-  return `${mb.toFixed(1)} MB`
+  if (mb >= 0.05) return `${mb.toFixed(1)} MB`
+  if (mb > 0) return `${Math.max(1, Math.round(mb * 1024))} KB`
+  return '0 MB'
 }
 
 /** 字节 → 可读文本 */
 function fmtBytes(b) {
   const mb = b / 1024 / 1024
   if (mb >= 1024) return `${(mb / 1024).toFixed(1)} GB`
-  return `${mb.toFixed(1)} MB`
+  if (mb >= 0.05) return `${mb.toFixed(1)} MB`
+  if (mb > 0) return `${Math.max(1, Math.round(mb * 1024))} KB`
+  return '0 MB'
 }
 
+export { fmtSize, fmtBytes }
+
 const fmtSizeFn = fmtSize
 
 async function refreshPackages(keyword = '') {
diff --git a/frontend/src/views/IgnoredView.vue b/frontend/src/views/IgnoredView.vue
index 02ea4f0..9b5d8de 100644
--- a/frontend/src/views/IgnoredView.vue
+++ b/frontend/src/views/IgnoredView.vue
@@ -1,6 +1,6 @@
 <script setup>
 import { computed } from 'vue'
-import { useStore } from '../store'
+import { useStore, fmtSize } from '../store'
 
 const { state, unignorePkg, refreshPackages } = useStore()
 
@@ -42,7 +42,7 @@ async function doUnignore(pkg) {
           <tr v-for="p in ignoredList" :key="p.name">
             <td><span class="pkg-cell">{{ p.name }}</span></td>
             <td><span class="num-cell">{{ p.versions }}</span></td>
-            <td><span class="num-cell">{{ p.size }} MB</span></td>
+            <td><span class="num-cell">{{ fmtSize(p.size) }}</span></td>
             <td><span class="ign-time">{{ p.ignoredAt || '—' }}</span></td>
             <td>
               <button class="btn unignore" @click="doUnignore(p)">↩️ 移出忽略</button>
diff --git a/frontend/src/views/OverviewView.vue b/frontend/src/views/OverviewView.vue
index 576789b..9262a70 100644
--- a/frontend/src/views/OverviewView.vue
+++ b/frontend/src/views/OverviewView.vue
@@ -7,7 +7,7 @@ import Top30Panel from '../components/Top30Panel.vue'
 import PackageCard from '../components/PackageCard.vue'
 import PackageDrawer from '../components/PackageDrawer.vue'
 import CleanDialog from '../components/CleanDialog.vue'
-import { useStore } from '../store'
+import { useStore, fmtSize } from '../store'
 
 const router = useRouter()
 const { state, stats, refreshAll, ignorePkg, unignorePkg, cleanPkg } = useStore()
@@ -86,7 +86,7 @@ function quickClean() {
     <div class="stats-2">
       <StatMini tone="blue" label="今日更新包数" ico="🆕" :main="String(stats.todayUpdated)" sub="今日有版本更新" link="查看" @link="router.push('/search')" />
       <StatMini tone="green" label="缓存版本总数" ico="🧩" :main="stats.totalVersions.toLocaleString()" sub="全部缓存包的版本数" link="查看" @link="router.push('/search')" />
-      <StatMini tone="orange" label="最大包" ico="🐘" :main="stats.maxPkg?.name || '—'" :unit="stats.maxPkg ? stats.maxPkg.size + ' MB' : ''" :sub="`${stats.maxPkg?.versions || 0} 个版本`" link="详情" @link="stats.maxPkg && openDrawer(stats.maxPkg)" />
+      <StatMini tone="orange" label="最大包" ico="🐘" :main="stats.maxPkg?.name || '—'" :unit="stats.maxPkg ? fmtSize(stats.maxPkg.size) : ''" :sub="`${stats.maxPkg?.versions || 0} 个版本`" link="详情" @link="stats.maxPkg && openDrawer(stats.maxPkg)" />
       <StatMini tone="purple" label="最老包时间" ico="⏳" :main="stats.oldestPkg?.lastUpdated || '—'" unit="⏰" :sub="stats.oldestPkg ? `${stats.oldestPkg.name} · 未更新` : ''" link="详情" @link="stats.oldestPkg && openDrawer(stats.oldestPkg)" />
       <StatMini tone="pink" label="版本数分布" ico="🧩" main=">15 版本" :unit="`${stats.warnCount} 个`" :sub="`超阈值共 ${warningExcess} 个版本`" link="查看" @link="router.push({ path: '/search', query: { status: 'warn' } })" />
     </div>
diff --git a/frontend/src/views/SearchView.vue b/frontend/src/views/SearchView.vue
index 7ff6f45..994d758 100644
--- a/frontend/src/views/SearchView.vue
+++ b/frontend/src/views/SearchView.vue
@@ -5,7 +5,7 @@ import PackageDrawer from '../components/PackageDrawer.vue'
 import CleanDialog from '../components/CleanDialog.vue'
 import StatusTag from '../components/StatusTag.vue'
 import PkgLogo from '../components/PkgLogo.vue'
-import { useStore } from '../store'
+import { useStore, fmtSize } from '../store'
 
 const { state, stats, refreshPackages, ignorePkg, unignorePkg, cleanPkg, deleteVersion } = useStore()
 const route = useRoute()
@@ -138,7 +138,7 @@ async function onCleanConfirmed(res) {
               </span>
             </td>
             <td><span class="num-cell" :class="{ over: p.versions > state.threshold.versionThreshold }">{{ p.versions }}</span></td>
-            <td><span class="num-cell">{{ p.size }} MB</span></td>
+            <td><span class="num-cell">{{ fmtSize(p.size) }}</span></td>
             <td><span class="date-cell">{{ p.lastUpdated || '—' }}</span></td>
             <td><StatusTag :status="p.status" /></td>
             <td @click.stop>