Index: usr.sbin/makefs/ffs.c
===================================================================
--- usr.sbin/makefs/ffs.c
+++ usr.sbin/makefs/ffs.c
@@ -324,7 +324,6 @@
 static void
 ffs_validate(const char *dir, fsnode *root, fsinfo_t *fsopts)
 {
-	int32_t	ncg = 1;
 #ifdef notyet
 	int32_t	spc, nspf, ncyl, fssize;
 #endif
@@ -395,22 +394,26 @@
 		fsopts->size =
 		    fsopts->size * (100 + fsopts->freeblockpc) / 100;
 
-		/* add space needed for superblocks */
 	/*
-	 * The old SBOFF (SBLOCK_UFS1) is used here because makefs is
-	 * typically used for small filesystems where space matters.
-	 * XXX make this an option.
+	 * Add space needed for superblock, cylblock and to store inodes.
+	 * All of those segments are aligned to the block size.
+	 * XXX: This has to match calculations done in ffs_mkfs.
 	 */
-	fsopts->size += (SBLOCK_UFS1 + SBLOCKSIZE) * ncg;
-		/* add space needed to store inodes, x3 for blockmaps, etc */
-	if (ffs_opts->version == 1)
-		fsopts->size += ncg * DINODE1_SIZE *
-		    roundup(fsopts->inodes / ncg, 
-			ffs_opts->bsize / DINODE1_SIZE);
-	else
-		fsopts->size += ncg * DINODE2_SIZE *
-		    roundup(fsopts->inodes / ncg, 
-			ffs_opts->bsize / DINODE2_SIZE);
+	if (ffs_opts->version == 1) {
+		fsopts->size +=
+		    roundup(SBLOCK_UFS1 + SBLOCKSIZE, ffs_opts->bsize);
+		fsopts->size += roundup(SBLOCKSIZE, ffs_opts->bsize);
+		fsopts->size += ffs_opts->bsize;
+		fsopts->size +=  DINODE1_SIZE *
+		    roundup(fsopts->inodes, ffs_opts->bsize / DINODE1_SIZE);
+	} else {
+		fsopts->size +=
+		    roundup(SBLOCK_UFS2 + SBLOCKSIZE, ffs_opts->bsize);
+		fsopts->size += roundup(SBLOCKSIZE, ffs_opts->bsize);
+		fsopts->size += ffs_opts->bsize;
+		fsopts->size += DINODE2_SIZE *
+		    roundup(fsopts->inodes, ffs_opts->bsize / DINODE2_SIZE);
+	}
 
 		/* add minfree */
 	if (ffs_opts->minfree > 0)