diff --git a/frontend/src/utils/formatBytes.js b/frontend/src/utils/formatBytes.js
new file mode 100644
index 0000000..aab18e6
--- /dev/null
+++ b/frontend/src/utils/formatBytes.js
@@ -0,0 +1,10 @@
+const UNITS = ['B', 'KB', 'MB', 'GB'];
+
+export function formatBytes(bytes) {
+  if (!bytes || bytes <= 0) return '0 B';
+  const exponent = Math.min(Math.floor(Math.log(bytes) / Math.log(1024)), UNITS.length - 1);
+  const value = bytes / 1024 ** exponent;
+  const rounded = Math.round(value * 10) / 10;
+  const formatted = Number.isInteger(rounded) ? String(rounded) : rounded.toFixed(1);
+  return `${formatted} ${UNITS[exponent]}`;
+}