diff --git a/doc/json_schema.json b/doc/json_schema.json
index 07061c18f..be2334b2e 100644
--- a/doc/json_schema.json
+++ b/doc/json_schema.json
@@ -889,6 +889,11 @@
                                         "title": "Set if unknown (unable to detect sizes) volumes should be printed",
                                         "default": false
                                     },
+                                    "useAvailable": {
+                                        "type": "boolean",
+                                        "title": "Use f_bavail (lpFreeBytesAvailableToCaller for Windows) instead of f_bfree to calculate used bytes",
+                                        "default": false
+                                    },
                                     "key": {
                                         "$ref": "#/$defs/key"
                                     },
diff --git a/src/data/help.txt b/src/data/help.txt
index 48a076e88..6c484d29f 100644
--- a/src/data/help.txt
+++ b/src/data/help.txt
@@ -130,6 +130,7 @@ Module specific options:
     --disk-show-hidden <?value>:             Set if hidden volumes should be printed. Default is false
     --disk-show-subvolumes <?value>:         Set if subvolumes should be printed. Default is false
     --disk-show-unknown <?value>:            Set if unknown (unable to detect sizes) volumes should be printed. Default is false
+    --disk-use-available <?value>:           Use f_bavail (lpFreeBytesAvailableToCaller for Windows) instead of f_bfree to calculate used bytes. Default is false
     --bluetooth-show-disconnected: <?value>: Set if disconnected bluetooth devices should be printed. Default is false
     --display-compact-type: <?string>:       Set if all displays should be printed in one line. Default is none
     --display-detect-name: <?value>:         Set if display name should be detected and printed (if supported). Default is false
diff --git a/src/detection/disk/disk.c b/src/detection/disk/disk.c
index 00eba85c0..3e92ca0eb 100644
--- a/src/detection/disk/disk.c
+++ b/src/detection/disk/disk.c
@@ -7,7 +7,7 @@ static int compareDisks(const void* disk1, const void* disk2)
     return ffStrbufCompAlphabetically(&((const FFDisk*) disk1)->mountpoint, &((const FFDisk*) disk2)->mountpoint);
 }
 
-const char* ffDetectDisks(FFlist* disks)
+const char* ffDetectDisks(FFDiskOptions* options, FFlist* disks)
 {
     const char* error = ffDetectDisksImpl(disks);
 
@@ -23,6 +23,12 @@ const char* ffDetectDisks(FFlist* disks)
     {
         if(disk->bytesTotal == 0)
             disk->type |= FF_DISK_VOLUME_TYPE_UNKNOWN_BIT;
+        else
+        {
+            disk->bytesUsed = disk->bytesTotal - (
+                options->calcType == FF_DISK_CALC_TYPE_FREE ? disk->bytesFree : disk->bytesAvailable
+            );
+        }
     }
 
     return NULL;
diff --git a/src/detection/disk/disk.h b/src/detection/disk/disk.h
index 24c28c9cf..fced34a92 100644
--- a/src/detection/disk/disk.h
+++ b/src/detection/disk/disk.h
@@ -13,6 +13,8 @@ typedef struct FFDisk
     FFDiskVolumeType type;
 
     uint64_t bytesUsed;
+    uint64_t bytesFree;
+    uint64_t bytesAvailable;
     uint64_t bytesTotal;
 
     uint32_t filesUsed;
@@ -23,6 +25,6 @@ typedef struct FFDisk
  * Returns a List of FFDisk, sorted alphabetically by mountpoint.
  * If error is not set, disks contains at least one disk.
  */
-const char* ffDetectDisks(FFlist* result /* list of FFDisk */);
+const char* ffDetectDisks(FFDiskOptions* options, FFlist* result /* list of FFDisk */);
 
 #endif
diff --git a/src/detection/disk/disk_bsd.c b/src/detection/disk/disk_bsd.c
index 8701f60bd..89d66b4ad 100644
--- a/src/detection/disk/disk_bsd.c
+++ b/src/detection/disk/disk_bsd.c
@@ -45,7 +45,9 @@ const char* ffDetectDisksImpl(FFlist* disks)
         #endif
 
         disk->bytesTotal = fs->f_blocks * fs->f_bsize;
-        disk->bytesUsed = disk->bytesTotal - ((uint64_t)fs->f_bfree * fs->f_bsize);
+        disk->bytesFree = (uint64_t)fs->f_bfree * fs->f_bsize;
+        disk->bytesAvailable = (uint64_t)fs->f_bavail * fs->f_bsize;
+        disk->bytesUsed = 0; // To be filled in ./disk.c
 
         disk->filesTotal = (uint32_t) fs->f_files;
         disk->filesUsed = (uint32_t) (disk->filesTotal - (uint64_t)fs->f_ffree);
diff --git a/src/detection/disk/disk_linux.c b/src/detection/disk/disk_linux.c
index 69a85ac64..1f0f6acd3 100644
--- a/src/detection/disk/disk_linux.c
+++ b/src/detection/disk/disk_linux.c
@@ -209,7 +209,9 @@ static void detectStats(FFDisk* disk)
         memset(&fs, 0, sizeof(struct statvfs)); //Set all values to 0, so our values get initialized to 0 too
 
     disk->bytesTotal = fs.f_blocks * fs.f_frsize;
-    disk->bytesUsed = disk->bytesTotal - (fs.f_bfree * fs.f_frsize);
+    disk->bytesFree = fs.f_bfree * fs.f_frsize;
+    disk->bytesAvailable = fs.f_bavail * fs.f_frsize;
+    disk->bytesUsed = 0; // To be filled in ./disk.c
 
     disk->filesTotal = (uint32_t) fs.f_files;
     disk->filesUsed = (uint32_t) (disk->filesTotal - fs.f_ffree);
diff --git a/src/detection/disk/disk_windows.c b/src/detection/disk/disk_windows.c
index ecda28889..291d59ba6 100644
--- a/src/detection/disk/disk_windows.c
+++ b/src/detection/disk/disk_windows.c
@@ -25,13 +25,18 @@ const char* ffDetectDisksImpl(FFlist* disks)
         FFDisk* disk = ffListAdd(disks);
         ffStrbufInitWS(&disk->mountpoint, mountpoint);
 
-        uint64_t bytesFree;
-        if(!GetDiskFreeSpaceExW(mountpoint, NULL, (PULARGE_INTEGER)&disk->bytesTotal, (PULARGE_INTEGER)&bytesFree))
+        if(!GetDiskFreeSpaceExW(
+            mountpoint,
+            (PULARGE_INTEGER)&disk->bytesAvailable,
+            (PULARGE_INTEGER)&disk->bytesTotal,
+            (PULARGE_INTEGER)&disk->bytesFree
+        ))
         {
             disk->bytesTotal = 0;
-            bytesFree = 0;
+            disk->bytesFree = 0;
+            disk->bytesAvailable = 0;
         }
-        disk->bytesUsed = disk->bytesTotal - bytesFree;
+        disk->bytesUsed = 0; // To be filled in ./disk.c
 
         if(driveType == DRIVE_REMOVABLE || driveType == DRIVE_REMOTE || driveType == DRIVE_CDROM)
             disk->type = FF_DISK_VOLUME_TYPE_EXTERNAL_BIT;
diff --git a/src/modules/disk/disk.c b/src/modules/disk/disk.c
index 8eed33b96..724061176 100644
--- a/src/modules/disk/disk.c
+++ b/src/modules/disk/disk.c
@@ -166,7 +166,7 @@ static void printAutodetected(FFDiskOptions* options, const FFlist* disks)
 void ffPrintDisk(FFDiskOptions* options)
 {
     FF_LIST_AUTO_DESTROY disks = ffListCreate(sizeof (FFDisk));
-    const char* error = ffDetectDisks(&disks);
+    const char* error = ffDetectDisks(options, &disks);
 
     if(error)
     {
@@ -195,6 +195,7 @@ void ffInitDiskOptions(FFDiskOptions* options)
 
     ffStrbufInit(&options->folders);
     options->showTypes = FF_DISK_VOLUME_TYPE_REGULAR_BIT | FF_DISK_VOLUME_TYPE_EXTERNAL_BIT;
+    options->calcType = FF_DISK_CALC_TYPE_FREE;
 }
 
 bool ffParseDiskCommandOptions(FFDiskOptions* options, const char* key, const char* value)
@@ -255,6 +256,15 @@ bool ffParseDiskCommandOptions(FFDiskOptions* options, const char* key, const ch
         return true;
     }
 
+    if (ffStrEqualsIgnCase(subKey, "use-available"))
+    {
+        if (ffOptionParseBoolean(value))
+            options->calcType = FF_DISK_CALC_TYPE_AVAILABLE;
+        else
+            options->calcType = FF_DISK_CALC_TYPE_FREE;
+        return true;
+    }
+
     return false;
 }
 
@@ -318,6 +328,15 @@ void ffParseDiskJsonObject(FFDiskOptions* options, yyjson_val* module)
             continue;
         }
 
+        if (ffStrEqualsIgnCase(key, "useAvailable"))
+        {
+            if (yyjson_get_bool(val))
+                options->calcType = FF_DISK_CALC_TYPE_AVAILABLE;
+            else
+                options->calcType = FF_DISK_CALC_TYPE_FREE;
+            continue;
+        }
+
         ffPrintError(FF_DISK_MODULE_NAME, 0, &options->moduleArgs, "Unknown JSON key %s", key);
     }
 }
diff --git a/src/modules/disk/option.h b/src/modules/disk/option.h
index 4b0789ad0..f24090c34 100644
--- a/src/modules/disk/option.h
+++ b/src/modules/disk/option.h
@@ -14,6 +14,12 @@ typedef enum FFDiskVolumeType
     FF_DISK_VOLUME_TYPE_UNKNOWN_BIT = 1 << 4,
 } FFDiskVolumeType;
 
+typedef enum FFDiskCalcType
+{
+    FF_DISK_CALC_TYPE_FREE,
+    FF_DISK_CALC_TYPE_AVAILABLE,
+} FFDiskCalcType;
+
 typedef struct FFDiskOptions
 {
     FFModuleBaseInfo moduleInfo;
@@ -21,4 +27,5 @@ typedef struct FFDiskOptions
 
     FFstrbuf folders;
     FFDiskVolumeType showTypes;
+    FFDiskCalcType calcType;
 } FFDiskOptions;