Question about 4k vs HD file sizes

[j.coffield]

I shot some video with my mavic pro in 4k/30. I edited it down to a 42 second clip added some music and rendered it out in 4k then again in 1080. The 4k file size is 316 mb and the HD file is 313 mb. i thought the file sizes would be significantly larger on the 4k but its only 3mb larger. Does this make sense?

 

[PortCanaveralFlorida]

Check your exported data rate and ensure that your mbps is the same, just a thought.

 

[Kilrah]

All depends on your settings. If you configure your program for the same datarate then they'll be the same size.
Point is you can typically use a lower datarate to get similar visual quality in a smaller resolution.