diff --git a/libraries/SD/examples/SD_Test/SD_Test.ino b/libraries/SD/examples/SD_Test/SD_Test.ino
index 69c59766..6059446e 100644
--- a/libraries/SD/examples/SD_Test/SD_Test.ino
+++ b/libraries/SD/examples/SD_Test/SD_Test.ino
@@ -212,6 +212,8 @@ void setup(){
     renameFile(SD, "/hello.txt", "/foo.txt");
     readFile(SD, "/foo.txt");
     testFileIO(SD, "/test.txt");
+    Serial.printf("Total space: %lluMB\n", SD.totalBytes() / (1024 * 1024));
+    Serial.printf("Used space: %lluMB\n", SD.usedBytes() / (1024 * 1024));
 }
 
 void loop(){
diff --git a/libraries/SD/src/SD.cpp b/libraries/SD/src/SD.cpp
index 65e68c0f..be307f39 100644
--- a/libraries/SD/src/SD.cpp
+++ b/libraries/SD/src/SD.cpp
@@ -14,6 +14,7 @@
 
 #include "vfs_api.h"
 #include "sd_diskio.h"
+#include "ff.h"
 #include "FS.h"
 #include "SD.h"
 
@@ -73,4 +74,32 @@ uint64_t SDFS::cardSize()
     return (uint64_t)sectors * sectorSize;
 }
 
+uint64_t SDFS::totalBytes()
+{
+	FATFS* fsinfo;
+	DWORD fre_clust;
+	if(f_getfree("0:",&fre_clust,&fsinfo)!= 0) return 0;
+    uint64_t size = (fsinfo->csize)*(fsinfo->n_fatent - 2)
+#if _MAX_SS != 512
+        *(fsinfo->ssize);
+#else
+        *512;
+#endif
+	return size;
+}
+
+uint64_t SDFS::usedBytes()
+{
+	FATFS* fsinfo;
+	DWORD fre_clust;
+	if(f_getfree("0:",&fre_clust,&fsinfo)!= 0) return 0;
+	uint64_t size = (fsinfo->csize)*((fsinfo->n_fatent - 2) - (fsinfo->free_clst))
+#if _MAX_SS != 512
+        *(fsinfo->ssize);
+#else
+        *512;
+#endif
+	return size;
+}
+
 SDFS SD = SDFS(FSImplPtr(new VFSImpl()));
diff --git a/libraries/SD/src/SD.h b/libraries/SD/src/SD.h
index cf49bb8f..54e41ce3 100644
--- a/libraries/SD/src/SD.h
+++ b/libraries/SD/src/SD.h
@@ -32,6 +32,8 @@ public:
     void end();
     sdcard_type_t cardType();
     uint64_t cardSize();
+    uint64_t totalBytes();
+    uint64_t usedBytes();
 };
 
 }
diff --git a/libraries/SD_MMC/examples/SDMMC_Test/SDMMC_Test.ino b/libraries/SD_MMC/examples/SDMMC_Test/SDMMC_Test.ino
index bfd98681..b9e87285 100644
--- a/libraries/SD_MMC/examples/SDMMC_Test/SDMMC_Test.ino
+++ b/libraries/SD_MMC/examples/SDMMC_Test/SDMMC_Test.ino
@@ -209,6 +209,8 @@ void setup(){
     renameFile(SD_MMC, "/hello.txt", "/foo.txt");
     readFile(SD_MMC, "/foo.txt");
     testFileIO(SD_MMC, "/test.txt");
+    Serial.printf("Total space: %lluMB\n", SD_MMC.totalBytes() / (1024 * 1024));
+    Serial.printf("Used space: %lluMB\n", SD_MMC.usedBytes() / (1024 * 1024));
 }
 
 void loop(){
diff --git a/libraries/SD_MMC/src/SD_MMC.cpp b/libraries/SD_MMC/src/SD_MMC.cpp
index 54b97c1e..d554413b 100644
--- a/libraries/SD_MMC/src/SD_MMC.cpp
+++ b/libraries/SD_MMC/src/SD_MMC.cpp
@@ -23,6 +23,7 @@ extern "C" {
 #include "driver/sdmmc_defs.h"
 #include "sdmmc_cmd.h"
 }
+#include "ff.h"
 #include "SD_MMC.h"
 
 using namespace fs;
@@ -98,5 +99,32 @@ uint64_t SDMMCFS::cardSize()
     return (uint64_t)_card->csd.capacity * _card->csd.sector_size;
 }
 
+uint64_t SDMMCFS::totalBytes()
+{
+	FATFS* fsinfo;
+	DWORD fre_clust;
+	if(f_getfree("0:",&fre_clust,&fsinfo)!= 0) return 0;
+    uint64_t size = (fsinfo->csize)*(fsinfo->n_fatent - 2)
+#if _MAX_SS != 512
+        *(fsinfo->ssize);
+#else
+        *512;
+#endif
+	return size;
+}
+
+uint64_t SDMMCFS::usedBytes()
+{
+	FATFS* fsinfo;
+	DWORD fre_clust;
+	if(f_getfree("0:",&fre_clust,&fsinfo)!= 0) return 0;
+	uint64_t size = (fsinfo->csize)*((fsinfo->n_fatent - 2) - (fsinfo->free_clst))
+#if _MAX_SS != 512
+        *(fsinfo->ssize);
+#else
+        *512;
+#endif
+	return size;
+}
 
 SDMMCFS SD_MMC = SDMMCFS(FSImplPtr(new VFSImpl()));
diff --git a/libraries/SD_MMC/src/SD_MMC.h b/libraries/SD_MMC/src/SD_MMC.h
index fad774cb..e3dc1543 100644
--- a/libraries/SD_MMC/src/SD_MMC.h
+++ b/libraries/SD_MMC/src/SD_MMC.h
@@ -32,6 +32,8 @@ public:
     void end();
     sdcard_type_t cardType();
     uint64_t cardSize();
+    uint64_t totalBytes();
+    uint64_t usedBytes();
 };
 
 }