Intiger meta value with '>=' returns posts with lower value

Question

My post has a custom post meta named duration. which has the video duration in seconds. Like,

Post 1's duration: 1

Post 2's duration: 56

Post 3's duration: 155

Post 4's duration: 7

Post 5's duration: 2

My args for wp query:

Array
(
    [post_type] => post
    [posts_per_page] => 45
    [paged] => 0
    [orderby] => modified
    [meta_query] => Array
        (
            [0] => Array
                (
                    [key] => duration
                    [value] => 30
                    [compare] => >=
                )

        )

);

The query returns post 2,3,4 but it should return only post 2 and 3. Any idea?

Answer 1

The meta type needs to be set as numeric.

'type'    => 'numeric',

The full Query:

Array
(
    [post_type] => post
    [posts_per_page] => 45
    [paged] => 0
    [orderby] => modified
    [meta_query] => Array
        (
            [0] => Array
                (
                    [key] => duration
                    [value] => 30
                    [type] => 'numeric';
                    [compare] => >=
                )

        )

);