diff --git a/arm9/src/install.c b/arm9/src/install.c
index 4772296..67b2ab9 100644
--- a/arm9/src/install.c
+++ b/arm9/src/install.c
@@ -447,10 +447,14 @@ bool install(char* fpath, bool systemTitle)
 		//get install size
 		iprintf("Install Size: ");
 		swiWaitForVBlank();
-		
+
+		u32 clusterSize = getDsiClusterSize();
 		unsigned long long fileSize = getRomSize(fpath);
-		unsigned long long installSize = fileSize + _getSaveDataSize(h);
-		if (tmdFound) installSize += 708;
+		if ((fileSize % clusterSize) != 0)
+			fileSize += clusterSize - (fileSize % clusterSize);
+		//file + saves + TMD (rounded up to cluster size)
+		unsigned long long installSize = fileSize + _getSaveDataSize(h) + clusterSize;
+		if (tmdFound) installSize += clusterSize; //ticket, rounded up to cluster size
 
 		printBytes(installSize);
 		iprintf("\n");
diff --git a/arm9/src/storage.c b/arm9/src/storage.c
index 4fdd564..74ebbf3 100644
--- a/arm9/src/storage.c
+++ b/arm9/src/storage.c
@@ -514,10 +514,7 @@ unsigned long long getDsiSize()
 
 unsigned long long getDsiFree()
 {
-	u32 blockSize = 0;
-	struct statvfs st;
-	if (statvfs("nand:/", &st) == 0)
-		blockSize = st.f_bsize;
+	u32 blockSize = getDsiClusterSize();
 
 	//Get free space by subtracting file sizes in nand folders
 	unsigned long long size = getDsiSize();
@@ -534,4 +531,13 @@ unsigned long long getDsiFree()
 	}
 
 	return size;
-}
\ No newline at end of file
+}
+
+u32 getDsiClusterSize()
+{
+	struct statvfs st;
+	if (statvfs(sdnandMode ? "sd:/" : "nand:/", &st) == 0)
+		return st.f_bsize;
+
+	return 0;
+}
diff --git a/arm9/src/storage.h b/arm9/src/storage.h
index 8701cf6..811d6a8 100644
--- a/arm9/src/storage.h
+++ b/arm9/src/storage.h
@@ -42,6 +42,7 @@ unsigned long long getSDCardFree();
 //internal storage
 unsigned long long getDsiSize();
 unsigned long long getDsiFree();
+u32 getDsiClusterSize();
 #define getDsiUsed() (getDSIStorageSize() - getDSIStorageFree())
 
 #endif
\ No newline at end of file