diff --git a/src/modules/hytale-patches/formatter.ts b/src/modules/hytale-patches/formatter.ts
index c930a38..b1bc65f 100644
--- a/src/modules/hytale-patches/formatter.ts
+++ b/src/modules/hytale-patches/formatter.ts
@@ -1,7 +1,20 @@
 import type { PatchesUpdate } from './tracker.js'
 
+function formatBytes(bytes: number): string {
+  const units = ['B', 'KiB', 'MiB', 'GiB']
+  let size = bytes
+  let unitIndex = 0
+
+  while (size >= 1024 && unitIndex < units.length - 1) {
+    size /= 1024
+    unitIndex++
+  }
+
+  return `${size.toFixed(1)} ${units[unitIndex]}`
+}
+
 export function formatPatchesUpdate(update: PatchesUpdate): string {
-  const { patchline, version, previousVersion, patchId } = update
+  const { patchline, version, previousVersion, patchId, patchSize } = update
   const emoji = patchline === 'release' ? '🎮' : '🧪'
 
   return `<b>${emoji} Hytale Game Patch Update</b>
@@ -9,5 +22,6 @@ export function formatPatchesUpdate(update: PatchesUpdate): string {
 <b>Patchline:</b> <code>${patchline}</code>
 <b>New version:</b> <code>${version}</code>
 ${previousVersion !== 'unknown' ? `<b>Previous:</b> <code>${previousVersion}</code>` : ''}
-${patchId ? `<b>Patch ID:</b> <code>${patchId}</code>` : ''}`
+${patchId ? `<b>Patch ID:</b> <code>${patchId}</code>` : ''}
+${patchSize ? `<b>Size:</b> ~<code>${formatBytes(patchSize)}</code>` : ''}`
 }
diff --git a/src/modules/hytale-patches/tracker.ts b/src/modules/hytale-patches/tracker.ts
index 111677d..7044e0e 100644
--- a/src/modules/hytale-patches/tracker.ts
+++ b/src/modules/hytale-patches/tracker.ts
@@ -14,6 +14,7 @@ export interface PatchesUpdate {
   version: string
   previousVersion: string
   patchId: number
+  patchSize?: number
 }
 
 const ENDPOINT = 'https://account-data.hytale.com/my-account/get-launcher-data?arch=amd64&os=windows'
@@ -22,10 +23,26 @@ const STATE_KEY = 'hytale-patches'
 export interface PatchesState {
   [patchline: string]: {
     lastVersion: string
+    lastPatchId: number
     lastCheck: string
   }
 }
 
+async function getPatchSize(patchline: string, fromPatch: number, toPatch: number): Promise<number | undefined> {
+  const url = `https://game-patches.hytale.com/patches/windows/amd64/${patchline}/${fromPatch}/${toPatch}.pwr`
+  try {
+    const response = await fetch(url, { method: 'HEAD' })
+    if (response.ok) {
+      const contentLength = response.headers.get('content-length')
+      return contentLength ? Number.parseInt(contentLength, 10) : undefined
+    }
+  }
+  catch {
+    // Silently fail if HEAD request fails
+  }
+  return undefined
+}
+
 export async function checkPatchesUpdate(
   stateStore: StateStore,
   patchlines: string[],
@@ -57,18 +74,24 @@ export async function checkPatchesUpdate(
 
     if (lastState?.lastVersion === currentVersion) {
       // No update
-      state[patchline] = { lastVersion: currentVersion, lastCheck: new Date().toISOString() }
+      state[patchline] = { lastVersion: currentVersion, lastPatchId: patchId, lastCheck: new Date().toISOString() }
       continue
     }
 
     // Update detected
-    state[patchline] = { lastVersion: currentVersion, lastCheck: new Date().toISOString() }
+    state[patchline] = { lastVersion: currentVersion, lastPatchId: patchId, lastCheck: new Date().toISOString() }
+
+    // Fetch patch size
+    const patchSize = lastState?.lastPatchId !== undefined
+      ? await getPatchSize(patchline, lastState.lastPatchId, patchId)
+      : undefined
 
     updates.push({
       patchline,
       version: currentVersion,
       previousVersion: lastState?.lastVersion ?? 'unknown',
       patchId,
+      patchSize,
     })
   }