diff --git a/bin/sde-create-iso b/bin/sde-create-iso
index c2117b3..af1ccce 100644
--- a/bin/sde-create-iso
+++ b/bin/sde-create-iso
@@ -76,16 +76,16 @@ fmtsize()
 	strings=$( echo $var | tr -d '[0-9]' )
 	if [-n "$numbers" ]; then
 		case "$var" in
-			cd)	media_size=700 ;;
-			dvd)	media_size=4700 ;;
-			  *)	media_size=700 ;;
+			cd)	media_size=$(( 700*1024*1024 )) ;;
+			dvd)	media_size=$(( 4700*1024*1024 )) ;;
+			  *)	media_size=$(( 700*1024*1024 )) ;;
 		esac
 	else
 		lsrings=$( echo $strings | tr "[:upper:]" "[:lower:]" )
 		case "$lstrings" in
-			k|kb|kib|kylobytes|kilobites)	media_size=$(( "$numbers"/1024 )) ;;
-			m|mb|mib|megabytes|megabites)	media_size="$numbers" ;;
-			g|gb|gib|gigabytes|gigabites)	media_size=$(( "$numbers"*1024 )) ;;
+			k|kb|kib|kylobytes|kilobites)	media_size=$(( "$numbers"*1024 )) ;;
+			m|mb|mib|megabytes|megabites)	media_size=$(( "$numbers"*1024*1024 )) ;;
+			g|gb|gib|gigabytes|gigabites)	media_size=$(( "$numbers"*1024*1024 )) ;;
 			                           *)	echo_abort 1 "$strings: Unknown size unit specified, aborting."
 		esac
 	fi