diff --git a/Documentation/btrfs-filesystem.txt b/Documentation/btrfs-filesystem.txt
index b0d5820e..6e63d2c9 100644
--- a/Documentation/btrfs-filesystem.txt
+++ b/Documentation/btrfs-filesystem.txt
@@ -17,8 +17,31 @@ resizing, defragment.
 
 SUBCOMMAND
 ----------
-*df* <path> [<path>...]::
+*df* [options] <path>::
 Show space usage information for a mount point.
++
+`Options`
++
+-b|--raw::::
+raw numbers in bytes, without the 'B' suffix
+-h::::
+print human friendly numbers, base 1024, this is the default
+-H::::
+print human friendly numbers, base 1000
+--iec::::
+select the 1024 base for the following options, according to the IEC standard
+--si::::
+select the 1000 base for the following options, according to the SI standard
+-k|--kbytes::::
+show sizes in KiB, or kB with --si
+-m|--mbytes::::
+show sizes in MiB, or mB with --si
+-g|--gbytes::::
+show sizes in GiB, or gB with --si
+-t|--tbytes::::
+show sizes in TiB, or tB with --si
+
+If conflicting options are passed, the last one takes precedence.
 
 *show* [--mounted|--all-devices|<path>|<uuid>|<device>|<label>]::
 Show the btrfs filesystem with some additional info.
diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index f5439145..bb5881ed 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -113,9 +113,18 @@ static const char * const filesystem_cmd_group_usage[] = {
 };
 
 static const char * const cmd_df_usage[] = {
-	"btrfs filesystem df <path>",
-	"Show space usage information for a mount point",
-	NULL
+       "btrfs filesystem df [options] <path>",
+       "Show space usage information for a mount point",
+	"-b|--raw           raw numbers in bytes",
+	"-h                 human friendly numbers, base 1024 (default)",
+	"-H                 human friendly numbers, base 1000",
+	"--iec              use 1024 as a base (KiB, MiB, GiB, TiB)",
+	"--si               use 1000 as a base (kB, mB, gB, tB)",
+	"-k|--kbytes        show sizes in KiB, or kB with --si",
+	"-m|--mbytes        show sizes in MiB, or mB with --si",
+	"-g|--gbytes        show sizes in GiB, or gB with --si",
+	"-t|--tbytes        show sizes in TiB, or tB with --si",
+       NULL
 };
 
 static char *group_type_str(u64 flag)
@@ -209,7 +218,7 @@ static int get_df(int fd, struct btrfs_ioctl_space_args **sargs_ret)
 	return 0;
 }
 
-static void print_df(struct btrfs_ioctl_space_args *sargs)
+static void print_df(struct btrfs_ioctl_space_args *sargs, unsigned unit_mode)
 {
 	u64 i;
 	struct btrfs_ioctl_space_info *sp = sargs->spaces;
@@ -218,8 +227,8 @@ static void print_df(struct btrfs_ioctl_space_args *sargs)
 		printf("%s, %s: total=%s, used=%s\n",
 			group_type_str(sp->flags),
 			group_profile_str(sp->flags),
-			pretty_size(sp->total_bytes),
-			pretty_size(sp->used_bytes));
+			pretty_size_mode(sp->total_bytes, unit_mode),
+			pretty_size_mode(sp->used_bytes, unit_mode));
 	}
 }
 
@@ -229,12 +238,62 @@ static int cmd_df(int argc, char **argv)
 	int ret;
 	int fd;
 	char *path;
-	DIR  *dirstream = NULL;
+	DIR *dirstream = NULL;
+	unsigned unit_mode = UNITS_DEFAULT;
 
-	if (check_argc_exact(argc, 2))
+	optind = 1;
+	while (1) {
+		int long_index;
+		static const struct option long_options[] = {
+			{ "raw", no_argument, NULL, 'b'},
+			{ "kbytes", no_argument, NULL, 'k'},
+			{ "mbytes", no_argument, NULL, 'm'},
+			{ "gbytes", no_argument, NULL, 'g'},
+			{ "tbytes", no_argument, NULL, 't'},
+			{ "si", no_argument, NULL, 256},
+			{ "iec", no_argument, NULL, 257},
+		};
+		int c = getopt_long(argc, argv, "bhHkmgt", long_options,
+					&long_index);
+		if (c < 0)
+			break;
+		switch (c) {
+		case 'b':
+			unit_mode = UNITS_RAW;
+			break;
+		case 'k':
+			units_set_base(&unit_mode, UNITS_KBYTES);
+			break;
+		case 'm':
+			units_set_base(&unit_mode, UNITS_MBYTES);
+			break;
+		case 'g':
+			units_set_base(&unit_mode, UNITS_GBYTES);
+			break;
+		case 't':
+			units_set_base(&unit_mode, UNITS_TBYTES);
+			break;
+		case 'h':
+			unit_mode = UNITS_HUMAN_BINARY;
+			break;
+		case 'H':
+			unit_mode = UNITS_HUMAN_DECIMAL;
+			break;
+		case 256:
+			units_set_mode(&unit_mode, UNITS_DECIMAL);
+			break;
+		case 257:
+			units_set_mode(&unit_mode, UNITS_BINARY);
+			break;
+		default:
+			usage(cmd_df_usage);
+		}
+	}
+
+	if (check_argc_max(argc, optind + 1))
 		usage(cmd_df_usage);
 
-	path = argv[1];
+	path = argv[optind];
 
 	fd = open_file_or_dir(path, &dirstream);
 	if (fd < 0) {
@@ -244,7 +303,7 @@ static int cmd_df(int argc, char **argv)
 	ret = get_df(fd, &sargs);
 
 	if (ret == 0) {
-		print_df(sargs);
+		print_df(sargs, unit_mode);
 		free(sargs);
 	} else {
 		fprintf(stderr, "ERROR: get_df failed %s\n", strerror(-ret));
diff --git a/utils.c b/utils.c
index bdb73999..e86292ac 100644
--- a/utils.c
+++ b/utils.c
@@ -1297,35 +1297,38 @@ out:
 static const char* unit_suffix_binary[] =
 	{ "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"};
 static const char* unit_suffix_decimal[] =
-	{ "B", "KB", "MB", "GB", "TB", "PB", "EB"};
+	{ "B", "kB", "mB", "gB", "tB", "pB", "eB"};
 
-int pretty_size_snprintf(u64 size, char *str, size_t str_size, int unit_mode)
+int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mode)
 {
 	int num_divs;
 	float fraction;
-	int base = 0;
+	u64 base = 0;
+	int mult = 0;
 	const char** suffix = NULL;
 	u64 last_size;
 
 	if (str_size == 0)
 		return 0;
 
-	if (unit_mode == UNITS_RAW) {
+	if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_RAW) {
 		snprintf(str, str_size, "%llu", size);
 		return 0;
 	}
 
-	if (unit_mode == UNITS_BINARY) {
+	if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_BINARY) {
 		base = 1024;
+		mult = 1024;
 		suffix = unit_suffix_binary;
-	} else if (unit_mode == UNITS_DECIMAL) {
+	} else if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_DECIMAL) {
 		base = 1000;
+		mult = 1000;
 		suffix = unit_suffix_decimal;
 	}
 
 	/* Unknown mode */
 	if (!base) {
-		fprintf(stderr, "INTERNAL ERROR: unknown unit base, mode %d",
+		fprintf(stderr, "INTERNAL ERROR: unknown unit base, mode %d\n",
 				unit_mode);
 		assert(0);
 		return -1;
@@ -1333,11 +1336,22 @@ int pretty_size_snprintf(u64 size, char *str, size_t str_size, int unit_mode)
 
 	num_divs = 0;
 	last_size = size;
-
-	while (size >= base) {
-		last_size = size;
-		size /= base;
-		num_divs++;
+	switch (unit_mode & UNITS_MODE_MASK) {
+	case UNITS_TBYTES: base *= mult; num_divs++;
+	case UNITS_GBYTES: base *= mult; num_divs++;
+	case UNITS_MBYTES: base *= mult; num_divs++;
+	case UNITS_KBYTES: num_divs++;
+			   break;
+	case UNITS_BYTES:
+			   base = 1;
+			   num_divs = 0;
+			   break;
+	default:
+		while (size >= mult) {
+			last_size = size;
+			size /= mult;
+			num_divs++;
+		}
 	}
 
 	if (num_divs >= ARRAY_SIZE(unit_suffix_binary)) {
@@ -2377,3 +2391,17 @@ int test_isdir(const char *path)
 
 	return S_ISDIR(st.st_mode);
 }
+
+void units_set_mode(unsigned *units, unsigned mode)
+{
+	unsigned base = *units & UNITS_MODE_MASK;
+
+	*units = base | mode;
+}
+
+void units_set_base(unsigned *units, unsigned base)
+{
+	unsigned mode = *units & ~UNITS_MODE_MASK;
+
+	*units = base | mode;
+}
diff --git a/utils.h b/utils.h
index e2b1ba80..aed03f23 100644
--- a/utils.h
+++ b/utils.h
@@ -48,12 +48,26 @@ void fixup_argv0(char **argv, const char *token);
 void set_argv0(char **argv);
 
 /*
- * Output mode of byte units
+ * Output modes of size
  */
-#define UNITS_RAW			(1)
-#define UNITS_BINARY			(2)
-#define UNITS_DECIMAL			(3)
-#define UNITS_HUMAN			UNITS_BINARY
+#define UNITS_RESERVED			(0)
+#define UNITS_BYTES			(1)
+#define UNITS_KBYTES			(2)
+#define UNITS_MBYTES			(3)
+#define UNITS_GBYTES			(4)
+#define UNITS_TBYTES			(5)
+#define UNITS_RAW			(1U << UNITS_MODE_SHIFT)
+#define UNITS_BINARY			(2U << UNITS_MODE_SHIFT)
+#define UNITS_DECIMAL			(3U << UNITS_MODE_SHIFT)
+#define UNITS_MODE_MASK			((1U << UNITS_MODE_SHIFT) - 1)
+#define UNITS_MODE_SHIFT		(8)
+#define UNITS_HUMAN_BINARY		(UNITS_BINARY)
+#define UNITS_HUMAN_DECIMAL		(UNITS_DECIMAL)
+#define UNITS_HUMAN			(UNITS_HUMAN_BINARY)
+#define UNITS_DEFAULT			(UNITS_HUMAN)
+
+void units_set_mode(unsigned *units, unsigned mode);
+void units_set_base(unsigned *units, unsigned base);
 
 int make_btrfs(int fd, const char *device, const char *label,
 	       char *fs_uuid, u64 blocks[6], u64 num_bytes, u32 nodesize,
@@ -76,12 +90,12 @@ int check_mounted_where(int fd, const char *file, char *where, int size,
 int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
 				 int super_offset);
 
-int pretty_size_snprintf(u64 size, char *str, size_t str_bytes, int unit_mode);
-#define pretty_size(size) 	pretty_size_mode(size, UNITS_BINARY)
+int pretty_size_snprintf(u64 size, char *str, size_t str_bytes, unsigned unit_mode);
+#define pretty_size(size) 	pretty_size_mode(size, UNITS_DEFAULT)
 #define pretty_size_mode(size, mode) 					      \
 	({								      \
 		static __thread char _str[32];				      \
-		(void)pretty_size_snprintf((size), _str, sizeof(_str), mode); \
+		(void)pretty_size_snprintf((size), _str, sizeof(_str), (mode)); \
 		_str;							      \
 	})