In the era of great image quality and resolution, 4K content is the new trend. 4k videos are no longer something unusual or fancy in 2022. But before downloading 4k videos, you need to know how much 128GB can be.

The formula for calculating 4k video size is based on this equation: “Size of a frame = Number of pixels x Size of a pixel”. If I keep it simple, a 128GB SD card can generally store up to 4.5 to 5 hours of 4k video (if based on 60fps).

Here in this article, I will understand briefly. How Much 4K Video Can 128 GB And 64 GB Hold, See the article below to find out more.

How to calculate 4K video size?

In this part of the article, we will walk you through the process of calculating the size of a 4k video. If you’ve researched original content about videos, you know that a video consists of multiple images. Technically, a video is a combination of several images.

The formula for calculating 4k video size lies in knowing a frame size.

A-frame size = number of pixels x size of pixels.

If we take the 4k resolution, for example, it will be 4096 x 2160. And if we take 8 bits for each channel as an example, the frame size becomes 4096 x 2160 x 8 = 70778880 bits. If you convert bits to bytes, the calculation becomes much easier for you.

8 bits = 1 byte

1024 bytes = 1 kilobyte

1024 kilobytes = 1 megabyte

That is, 7077880 bits is equal to 7077880 / (8 x 1024 x 1024) = 8.43 MB.

How much memory do I need for a 4k video?

One hour of 4K video requires approximately 110GB of storage; This translates to 2GB per minute. Obviously, since it requires more space than standard video footage, you need to take this into account when buying a 4k SD card. Remember, your memory card must support the largest 4k video size.

4K or Ultra HD?

You can never tell how fast technology is developing. One day you hear that 4k resolution is better and another day, it is replaced by Ultra HD. The time is coming when you’ll be ready to bring a television with 8K video resolution into your home.

There are also horizontal pixels and some vertical pixels in 4k resolution. Horizontal pixels are 4096 pixels. Vertical pixels are 2160 pixels. 4k used to mean 4000, but it is now 4096 x 2160 pixels, sometimes called 4k2k. Whereas an Ultra High Definition UHD may never reach the 4k resolution level due to its small horizontal pixels.

An Ultra-HD resolution consists of 3840x 2160 pixels, which is enough to refer to full high definition. Some TVs and other displays with 3840×2169 pixels are often labeled as 4k resolution displays.

What memory card can I use for video?

Historically, the two most common memory card formats have been Secure Digital (SD) and Compact Flash (CF) cards. SD cards are used in all types of cameras, from point-and-shoot models to professional digital cinema cameras, with smaller microSD cards now often used in cameras such as HD camcorders and aerial cameras. CF cards are stronger and more durable and are often used in high-end DSLR and digital cinema cameras.

Many cameras that record digital video offer two memory card slots. For example, Panasonic GH5S cameras have two SD card slots, but some cameras offer a mix of card formats (probably CF and SD) in their dual slots. The main advantage of dual card slots is that once one card is full of data, you can continue recording to the other.

Understand the speed of reading versus writing

Memory cards have read and write speed. Write speed describes how fast images or videos can be saved to the card. Read speed refers to how quickly data can be retrieved from the card; For example, when transferring your video footage to an external hard drive.

Card speed is represented by a multiplication value (each ‘x’ value represents 0.15MB / sec, so multiplying 2000x by 0.15MB / sec gives 300MB / sec) or a rating of ‘class ‘Is. Class rating refers to the minimum write performance for video recording: a Class 2 card can handle continuous data writing at 2MB / s, a Class 4 card at 4MB / s, a Class 6 at 6MB / s, and Class 10 write data at the fastest speed. 10 MB. / sec.

There is also a category V classification, which was created by the SD Association. The highest V rating is V90, which indicates a minimum sustained speed of 90MB / s. Other class V classifications are V60, V30, V10, and V6, with numbers indicating speeds in MB / s.

For memory cards, it is better to do what is known as “sustainable speed” rather than “achievable speed”. As a general rule of thumb, if you’re recording 4K RAW, you’ll need at least 75MB / s write speed to keep it up without dropping frames.

UHS speed classes indicate how fast video content can be transferred to the memory card. UHS-I allows maximum transfer speeds of 104MB / s, while UHS-II allows speeds of up to 312MB / s. Within the UHS speed class, there are two designations, U1 and U3, which represent minimum write speeds of 10MB / s and 30MB / s, respectively.

CFast 2.0 cards were once leaders in terms of speed. The original CFast 2.0 card from 2013 promised read speeds of up to 450MB / sec and write speeds of up to 350MB / sec.

In their current versions, CFast cards have a theoretical limit of 600MB / sec and XQD cards of 1000MB / sec. They are ideal for recording videos with resolutions of 4K and more.

It shows the capacity of each memory card, for example, 4GB to 512GB. The capacity value is always double, so the card capacity will be 4GB, 8GB, 16GB, 32GB, 64GB, etc. Naturally, the higher the card’s capacity to store your video footage, the higher the value.

Conclusion

Before buying an SD card, think about the type of video it records. Do you need hours of footage on the SD card?

Keep in mind that choosing a larger card now can help you avoid the need to upgrade to a larger card later.

For example, you can currently record 4K video at 25MB / s, but after updating your camera firmware, you can start using the highest bitrate codec.

Getting a bigger SD card now can also prepare your gear for the cameras of the future. The next generation is likely to support 4K video at higher frame rates, allowing bit rates to exceed 400 Mbps.