diff --git a/scripts/cloudron-setup b/scripts/cloudron-setup
index cc34dc5fa..35cc1e68b 100755
--- a/scripts/cloudron-setup
+++ b/scripts/cloudron-setup
@@ -15,7 +15,8 @@ readonly MINIMUM_MEMORY="990"     # this is mostly reported for 1GB main memory
 # copied from cloudron-resize-fs.sh
 readonly physical_memory=$(free -m | awk '/Mem:/ { print $2 }')
 readonly disk_device="$(for d in $(find /dev -type b); do [ "$(mountpoint -d /)" = "$(mountpoint -x $d)" ] && echo $d && break; done)"
-readonly disk_size_gb=$(fdisk -l ${disk_device} | grep "Disk ${disk_device}" | awk '{ printf "%.0f", $3 }')
+readonly disk_size_bytes=$(fdisk -l ${disk_device} | grep "Disk ${disk_device}" | awk '{ printf "%d", $5 }')
+readonly disk_size_gb=$((${disk_size_bytes}/1024/1024/1024))
 
 # verify the system has minimum requirements met
 if [[ "${physical_memory}" -lt "${MINIMUM_MEMORY}" ]]; then
diff --git a/setup/start/cloudron-resize-fs.sh b/setup/start/cloudron-resize-fs.sh
index d0a7c1a7a..4bf770895 100755
--- a/setup/start/cloudron-resize-fs.sh
+++ b/setup/start/cloudron-resize-fs.sh
@@ -16,8 +16,8 @@ existing_swap=$(cat /proc/meminfo | grep SwapTotal | awk '{ printf "%.0f", $2/10
 readonly physical_memory=$(free -m | awk '/Mem:/ { print $2 }')
 readonly swap_size=$((${physical_memory} - ${existing_swap})) # if you change this, fix enoughResourcesAvailable() in client.js
 readonly app_count=$((${physical_memory} / 200)) # estimated app count
-readonly disk_size_gb=$(fdisk -l ${disk_device} | grep "Disk ${disk_device}" | awk '{ printf "%.0f", $3 }')
-readonly disk_size=$((disk_size_gb * 1024))
+readonly disk_size_bytes=$(fdisk -l ${disk_device} | grep "Disk ${disk_device}" | awk '{ printf "%d", $5 }') # can't rely on fdisk human readable units, using bytes instead
+readonly disk_size=$((${disk_size_bytes}/1024/1024))
 readonly system_size=10240 # 10 gigs for system libs, apps images, installer, box code and tmp
 readonly ext4_reserved=$((disk_size * 5 / 100)) # this can be changes using tune2fs -m percent /dev/vda1