diff --git a/src/pages/AdminBanSystem.tsx b/src/pages/AdminBanSystem.tsx
index 39932fc..5a7ee2d 100644
--- a/src/pages/AdminBanSystem.tsx
+++ b/src/pages/AdminBanSystem.tsx
@@ -411,8 +411,8 @@ export default function AdminBanSystem() {
   const formatBytes = (bytes: number) => {
     if (bytes === 0) return '0 B';
     const k = 1024;
-    const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
-    const i = Math.floor(Math.log(bytes) / Math.log(k));
+    const sizes = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB'];
+    const i = Math.min(Math.floor(Math.log(bytes) / Math.log(k)), sizes.length - 1);
     return `${parseFloat((bytes / Math.pow(k, i)).toFixed(2))} ${sizes[i]}`;
   };
 
diff --git a/src/pages/AdminRemnawave.tsx b/src/pages/AdminRemnawave.tsx
index 45093c4..35b6126 100644
--- a/src/pages/AdminRemnawave.tsx
+++ b/src/pages/AdminRemnawave.tsx
@@ -42,8 +42,8 @@ const BackIcon = () => (
 const formatBytes = (bytes: number): string => {
   if (bytes === 0) return '0 B';
   const k = 1024;
-  const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
-  const i = Math.floor(Math.log(bytes) / Math.log(k));
+  const sizes = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB'];
+  const i = Math.min(Math.floor(Math.log(bytes) / Math.log(k)), sizes.length - 1);
   return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
 };
 
@@ -363,9 +363,15 @@ function OverviewTab({ stats, isLoading, onRefresh }: OverviewTabProps) {
     );
   }
 
+  // Use (total - available) instead of raw "used" to exclude disk cache/buffers
+  // This matches what htop/free show as actual application memory usage
+  const memoryActualUsed =
+    stats.server_info.memory_available > 0
+      ? stats.server_info.memory_total - stats.server_info.memory_available
+      : stats.server_info.memory_used;
   const memoryUsedPercent =
     stats.server_info.memory_total > 0
-      ? Math.round((stats.server_info.memory_used / stats.server_info.memory_total) * 100)
+      ? Math.round((memoryActualUsed / stats.server_info.memory_total) * 100)
       : 0;
 
   return (
@@ -446,7 +452,7 @@ function OverviewTab({ stats, isLoading, onRefresh }: OverviewTabProps) {
           <StatCard
             label={t('admin.remnawave.overview.memory', 'Memory')}
             value={`${memoryUsedPercent}%`}
-            subValue={`${formatBytes(stats.server_info.memory_used)} / ${formatBytes(stats.server_info.memory_total)}`}
+            subValue={`${formatBytes(memoryActualUsed)} / ${formatBytes(stats.server_info.memory_total)}`}
             icon={<span className="text-lg">💾</span>}
             color={memoryUsedPercent > 80 ? 'red' : memoryUsedPercent > 60 ? 'orange' : 'green'}
           />
diff --git a/src/pages/AdminTrafficUsage.tsx b/src/pages/AdminTrafficUsage.tsx
index b123ddb..b28c07d 100644
--- a/src/pages/AdminTrafficUsage.tsx
+++ b/src/pages/AdminTrafficUsage.tsx
@@ -35,8 +35,8 @@ declare module '@tanstack/react-table' {
 const formatBytes = (bytes: number): string => {
   if (!Number.isFinite(bytes) || bytes <= 0) return '0 B';
   const k = 1024;
-  const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
-  const i = Math.floor(Math.log(bytes) / Math.log(k));
+  const sizes = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB'];
+  const i = Math.min(Math.floor(Math.log(bytes) / Math.log(k)), sizes.length - 1);
   return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
 };
 
diff --git a/src/pages/AdminUserDetail.tsx b/src/pages/AdminUserDetail.tsx
index 0d690ba..74a5f20 100644
--- a/src/pages/AdminUserDetail.tsx
+++ b/src/pages/AdminUserDetail.tsx
@@ -766,10 +766,10 @@ export default function AdminUserDetail() {
 
   const formatBytes = (bytes: number) => {
     if (bytes === 0) return '0 B';
-    if (bytes < 1024) return `${bytes} B`;
-    if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
-    if (bytes < 1024 * 1024 * 1024) return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
-    return `${(bytes / (1024 * 1024 * 1024)).toFixed(2)} GB`;
+    const k = 1024;
+    const sizes = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB'];
+    const i = Math.min(Math.floor(Math.log(bytes) / Math.log(k)), sizes.length - 1);
+    return `${parseFloat((bytes / Math.pow(k, i)).toFixed(2))} ${sizes[i]}`;
   };
 
   const copyToClipboard = async (text: string) => {