How Much 4K Video Can 128GB Hold?

Looking to record 4K video? See how much 4K video fits on a 128GB memory card at various video bitrates. Calculate how much 4K footage you can get with this interactive chart and calculator.

128GB SD Card
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The amount of storage space a video file takes up is determined by what is known as video bitrate.

A higher bitrate uses more data to encode each second of video, resulting in less compression, higher potential image quality, and larger file size. Conversely, a lower bitrate uses less data to encode each second of video, resulting in more compression, lower image quality, and smaller file size.

The encoding bitrate is determined by your camera’s capabilities and by the settings you use. High-end cameras can encode 4K video at 400 Mb/s or more. Cameras such as action cameras and drones can record 4K video in the 100 Mb/s to 200 Mb/s range. Lower-level or older cameras, such as early-generation 4K cameras, recorded at closer to 60 Mb/s. YouTube recommends a bitrate of between 35 and 68 for 4K videos you upload. 1

Mbps and Mb/s are different ways of writing the same thing. Both refer to megabits per second. They both use a lowercase “b.” Video bitrate is conventionally measured in Mb/s.

If the “B” is capitalized, as in MB/s or MBps, it refers to megabytes per second. There are 8 bits in a byte, so there are 8 megabits in a megabyte. The speed of memory cards is conventionally measured in MB/s.

So there’s a wide range of bitrates that can be used to encode 4K video. And that means there’s a wide range in answering how much 4K video can fit on a 128GB memory card. It can be anywhere from 8 hours to under an hour, depending on the bitrate used. For example, on 128GB, you can fit over 8 hours of 4K footage at a low bitrate of 35 Mbps or about 44 minutes of 4K footage recorded on a high-end camera at 400 Mb/s.

Here’s a table that shows how much 4K video you can fit in 128GB at various bitrates.

4K Video on a 128GB Memory Card Chart

Video Bitrate (Mbps)Duration
358 hours and 19 minutes
456 hours and 28 minutes
505 hours and 50 minutes
535 hours and 30 minutes
604 hours and 51 minutes
684 hours and 17 minutes
704 hours and 10 minutes
783 hours and 44 minutes
803 hours and 38 minutes
903 hours and 14 minutes
1002 hours and 55 minutes
1202 hours and 26 minutes
1252 hours and 20 minutes
1501 hour and 57 minutes
1751 hour and 40 minutes
2001 hour and 27 minutes
2301 hour and 16 minutes
2501 hour and 10 minutes
30058 minutes
32055 minutes
40044 minutes

4K Video on 128GB Memory Card Calculator

Here’s another option if you need a bitrate that’s not in the chart above.

On a 128GB memory card, you can fit around
0 minutes of 4K video footage at
a bitrate of 100 Mb/s.
This corresponds to about 12.5 megabytes per second of footage, or 750 megabytes per minute.

Does Framerate Affect 4K Video File Size?

Sort of.

Framerate and resolution don’t play direct roles in how much storage space a video file takes up. For instance, 4K30 video encoded at 100 Mbps will take up the same amount of storage space as 4K60 video encoded at 100 Mpbs, which is the same as a 1080p120 file encoded at 100 Mbps.

But they do play indirect roles. And that’s because you get better image quality if you use a higher bitrate when you record at a high framerate. With more frames and higher resolution, there’s more visual information to encode. And so there’s a benefit to using a higher bitrate with those.

So camera manufacturers will often bump up the bitrate along with the framerate. For instance, a camera will usually use a higher bitrate for 1080p240 video than it will for 1080p30. But that’s because of a design choice by the manufacturer to try to keep maximum detail and picture quality in the 1080p240 video by recording it at a higher bitrate. It’s not the framerate directly that’s using more data, it’s the higher bitrate being used to encode video at that framerate setting.

The relationship between framerate and storage size is more direct with high-end codecs such as Apple ProRes and Cineform, where the bitrate, or data rate, is designed to increase along with increasing framerate. That’s where it’s easy to get data rates up over 1900 Mbps, and it’s to do with a different approach to encoding. (You can read a much more technical discussion of how framerate increases data rate in the Apple ProRes codecs in this Apple white paper.) With codecs such as H.264 or HEVC (H.265), which are designed as much for sharing video as for recording, there’s more emphasis on the target bitrate and keeping filesize small. It’s even more direct with RAW capture.

128GB Memory Cards

Here are some fast 128GB memory cards in various form factors.

128GB microSD Cards

ProGrade Digital V60 UHS-II 128GB microSDXC
  • Type: microSDXC
  • Video Speed Class: V90
  • UHS Speed Class: UHS-II
  • Rated read speed: 250 MB/s
  • Rated write speed: 130 MB/s
SanDisk Extreme Pro V30 128GB microSDXC
  • Type: microSDXC
  • Video Speed Class: V30
  • UHS Speed Class: UHS-I
  • Rated read speed: 200 MB/s
  • Rated write speed: 90 MB/s

128GB SD Cards

Lexar Professional 2000x Gold V90 UHS-II 128GB SDXC
  • Type: SDXC
  • Video Speed Class: V90
  • UHS Speed Class: UHS-II
  • Rated read speed: 300
Kingston Canvas React Plus V90 UHS-II 128GB SDXC
  • Type: SDXC
  • Video Speed Class: V90
  • UHS Speed Class: UHS-II
  • Rated read speed: 300
  • Rated write speed: 260
ProGrade Digital V90 UHS-II 128GB SDXC
  • Type: SDXC
  • Video Speed Class: V90
  • UHS Speed Class: UHS-II
  • Rated read speed: 300
  • Rated write speed: 250

128GB CFexpress Type B Cards

SanDisk Extreme Pro 128GB CFexpress Type B
  • Type: CFexpress Type B
  • Rated read speed: 1700
  • Rated read speed: 1200
Lexar Professional 128GB CFexpress Type B
  • Type: CFexpress Type B
  • Rated read speed: 1750
  • Rated read speed: 1000
Delkin Devices Power 128GB CFexpress Type B
  • Type: CFexpress Type B
  • Rated read speed: 1730
  • Rated read speed: 1540

Memory Card Tools

Here are a few other related tools I’ve put together that can be useful when working with memory cards and data rates.

Converting Mbps to MB/s & X Speed Rating to MB/s

Another related and common calculation that often needs to be done when working with memory cards is converting the convention for measuring video bitrate (Mbps, Mb/s, or megabits per second) to the convention for measuring the speed of memory cards (MBps, MB/s, or megabytes per second).

So I’ve put together a simple calculator for that separately. You can find it here:

Memory Card Size Calculators

If you’re trying to figure out what size memory card to buy, it can be useful to know how much video footage from the camera you can fit on a card. Here are a few tools that can be useful for that:

Working with Memory Cards

Here are some related posts for making sense of memory cards and working with them.

  1. More specifically, YouTube recommends a bitrate of 35-45 Mb/s for 4K SDR video for footage recorded at framerates of 24, 25, or 30 fps or from 53-68 Mb/s for footage recorded at 48, 50, or 60 fps. For 4K HDR video, they recommend 44-56 Mb/s for standard framerates (24, 25, 30) or 66-85 Mb/s for high framerates (48, 50, 60).[]

Images and product information from Amazon PA-API were last updated on 2023-09-26 at 11:50. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon Site at the time of purchase will apply to the purchase of this product.

David Coleman / Photographer

David Coleman

I'm a professional freelance travel photographer based in Washington DC. Seven continents, up mountains, underwater, and a bunch of places in between. My images have appeared in numerous publications, and you can check out some of my travel photography here. More »

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