Search code examples
phpfilesize

determine image file size php

I have this code for checking max image size allowed: The one below is for 4 MB

elseif (round($_FILES['image_upload_file']["size"] / 1024) > 4096) {
$output['error']= "You can upload file size up to 4 MB";

I don't understand this calculation and approaches from the internet is making it more confusing

I wanted the size for

  • 8 MB
Solution

  • PHP $_FILES["image_upload_file"]["size"] variable return the value of file size in BYTES. So, for check the file size you have two option,

    1. Convert your checking limit into BYTES, and check with the $_FILES["image_upload_file"]["size"] value. As, 5MB= 5000000KB, 6MB= 6000000KB, 8MB= 8000000KB and so on. (Values are simplified)
    2. Convert the $_FILES["image_upload_file"]["size"] value in to MB and check.

    For me check the value in BYTES. It is more easier and you no need to calculate any thing.
    In your example, the values are calculate into KB and then checking. As, $_FILES['image_upload_file']["size"] / 1024 return value in KB and 4MB= 4096 KB. So, your internet code also right.
    If you want to use your internet code for 8MB then change the 4096 to 8192. It will work same.
    Hope, now you understand the code.