With over 8 million pixels compared to about 2 million of 1080p recording, 4K videos take up a lot of storage space. In our testing, across all 4K capable smartphones, on average, one second of footage took up about 11.6MB of storage space. In comparison, one second of 1080p footage used up only 2.2MB. Here’s a rough idea of how much storage space you will need to record 4K movies:
As you can see, recording in 4K will quickly use up your phone’s storage capacity. As such, it is recommended you use a high capacity microSD card to store your movies. Fortunately, Samsung, Sony and LG’s 4K capable smartphones all have microSD card slots with support up to 128GB capacity. It’s also a good idea to invest in a high speed memory card to ensure your video is recorded smoothly without buffering and slowdowns that can occur with free or entry-level memory cards.