diff --git a/README.md b/README.md
index bcc01dc..add393a 100644
--- a/README.md
+++ b/README.md
@@ -42,8 +42,9 @@ kill every wine process including processes hanging
 convert animated .webp at $1 (path) to a gif
 
 ### image_compress.sh 
-Usage: `./image_compress.sh <input> <output.jpg> <size in bytes>`  
+Usage: `./image_compress.sh <input> <output.jpg> <target size>`  
 Compress an image until it's below a specified target size. Output format is JPEG, regardless of the input format.  
+The target size can be without unit (default to bytes). Or in B, KB or MB, for bytes, kilo bytes and mega bytes (not case sensitive).  
 (requires ImageMagick)
 
 ### convert_md_to_pdf.sh
diff --git a/image_compress.sh b/image_compress.sh
index 938242d..786fa26 100755
--- a/image_compress.sh
+++ b/image_compress.sh
@@ -2,13 +2,38 @@
 
 input="$1"
 output="$2"
-target_size=$3
+target_size_raw="$3"
 
-if [[ -z "$input" || -z "$output" || -z "$target_size" ]]; then
-    echo "Usage: $0 input output.jpg <target size in bytes>"
+if [[ -z "$input" || -z "$output" || -z "$target_size_raw" ]]; then
+    echo "Usage: $0 input output.jpg <target size>"
     exit 1
 fi
 
+parse_size() {
+    local size="$1"
+
+    size=$(echo "$size" | tr '[:lower:]' '[:upper:]' | tr -d ' ')
+
+    if [[ "$size" =~ ^([0-9]+(\.[0-9]+)?)(B|KB|MB)?$ ]]; then
+        value="${BASH_REMATCH[1]}"
+        unit="${BASH_REMATCH[3]}"
+
+        case "$unit" in
+            ""|"B") multiplier=1 ;;
+            "KB") multiplier=1024 ;;
+            "MB") multiplier=$((1024 * 1024)) ;;
+            *) echo "Invalid size unit: $unit"; exit 1 ;;
+        esac
+
+        awk "BEGIN {printf \"%d\", $value * $multiplier}"
+    else
+        echo "Invalid size format: $size"
+        exit 1
+    fi
+}
+
+target_size=$(parse_size "$target_size_raw")
+
 compress_and_get_size() {
     local q=$1
     magick "$work" -strip -interlace Plane -quality "$q" "$output"