How Many Photos Can a Memory Card Hold

Focused on camera models, lenses, and external flash units, you don’t pay too much attention to ordinary little accessories such as memory cards and batteries. However, when the memory card is full or the battery is low, your pricey camera gear is useless and the photo session is ruined.

So it pays off to get the right memory card for your camera. Especially in wildlife photography where you fire off bursts of shots that can quickly fill up the camera buffer if the memory card isn’t up for the speed your camera needs to load off the images on to the card.

Memory cards have two main characteristics: speed of reading/writing and size.

Of course, you want the fastest speed possible and the largest size, but you should prepare to pay the price. Although memory cards are fairly inexpensive, twice the size means twice the price. Furthermore, most of the time, you empty the card as soon as you get to a laptop and store your photos safely using a cloud service or a hard disk. So, why pay more for a large card that stays empty? Instead, you should know how many photos a memory card can hold and choose the right card size for your purposes.

Understanding the Size of a Memory Card

The size of a memory card is measured in bytes, the unit for data storage capacity. The first memory card ever sold had 8MB, meaning 8 x 1024 x 1024 bytes. Today, you can hardly find a card under 16GB, meaning 16 x 1024 x 1024 x 1024 bytes, a thousand times larger than the first one.

The biggest memory cards available are over 1TB, meaning 1024 x 1024 x 1024 x 1024 bytes. It costs almost $500, and not all cameras support it, but you can hardly run out of storage space for your photographs or videos. SanDisk’s 1TB microSD card is designed mostly for video recording.

As it is one of the most important two features of a memory card, you can read the size on the front of the card. It’s impossible to miss it.

How to Choose the Best Memory Card for Your Camera

Size and speed aren’t the only parameters that matter. The first thing you have to do before buying a memory card is to read your camera specifications and find out the maximum memory card capacity it supports. For example, Canon EOS 1500D supports a 256GB card, while Canon EOS 1000D supports only a 32GB card.

So, there are differences even between camera models from the same manufacturer. If you need more storage space than your camera can support, buy multiple small memory cards and take them with you anywhere you go. A labeling or organizing system may help you keep a count of each card loading history. Make sure you empty the cards when you have the chance.

The choice you make also depends on the type of camera you have. A point-and-shoot camera saves images only in JPEG format. The highest resolution possible with a Canon IXUS 190 is 5152 x 3864 pixels, and it has an average file size of 8MB (even lower if you compress the image).

On the other hand, a mirrorless APS-C or full frame will allow you to shoot in RAW file format and keep all the details in the scene. However, the average file size of a RAW image file with the same 5152 x 3864 pixels resolution is around 26MB. Therefore, you can buy a smaller memory card for a compact camera than a professional camera.

You should take into consideration your photographer habits as well. Think about how many images you want the memory card to hold. You may be an avid travel or landscape photographer who often doesn’t have time to empty the card, in which case you need a larger card.

Wildlife and macro photographers tend to shoot in burst of shots many times, which can make the card fill up quickly.

How Many Photo can Your Memory Card Hold

The number of photos your card can hold depends on the size of the card and the size of the photographs you take. Most cameras allow you to choose between multiple resolutions and image formats such as JPEG, TIFF, and RAW.

TIFF and RAW are usually uncompressed file formats, while JPEG is a compressed format. The more you compress the image, the smaller the file size on the card will be. However, keep in mind that compressed images have lower quality.

Once you take a photograph, you can’t change its format and thus its size on the card. But if you struggle with a lack of storage space, you can lower the resolution or choose a less space-consuming image format. Most DSLR and mirrorless cameras take good pictures even at low resolutions.

To find out how many photos your memory card can hold, divide the size of the card by the file size of the image. Remember that a GB is 1024 times bigger than an MB.

How to Calculate the File Size for a JPEG Photograph

You know already that a digital image has a dimension in pixels called resolution. Each camera model provides a series of resolutions for you to choose from. For example, Nikon D7500 provides the following image resolutions: 5568 x 3712, 4176 x 2784, 2784 x 1856, 4272 x 2848, 3200 x 2136, and 2128 x 1424 pixels. Nikon Z6 has three image resolutions: 6000 × 4000, 4496 × 3000, and 2992 × 2000 pixels called large, medium, and small. As you can see, different camera models have different resolutions even if they have the same manufacturer.

Each file format uses a number of bits (1/8 of a byte) per pixel to store image data such as color and other information. An uncompressed JPEG file uses 24 bits per pixel, meaning 8 bits (1 byte) for each of the three primary colors, red, green, and blue (RGB). So, a 6000 × 4000 pixels uncompressed JPEG file will take 6000 × 4000 x 3 bytes, meaning 68.66 MB.

However, no digital camera provides 100% lossless JPEG compression. Nikon, for example, uses three types of JPEG files called FINE (highest quality, low compression), NORMAL, and BASIC (lowest quality, high compression).

How to Calculate the File Size for a RAW Photograph

RAW file formats are even more complicated. They usually have 12 or 14 bits per pixel and can be uncompressed, compressed with zero lost, or compressed with a low compression ratio. They also register more information than a JPEG and, as a result, require more storage space on the memory card.

An uncompressed 12bit per pixel RAW file with a 6000 × 4000 pixels resolution needs 34.33MB.

Moreover, RAW files carry additional information, which increases their file size even more.

Fortunately, the manufacturers provide tables with file sizes for their formats.

Concluding words

Although JPEG and RAW file formats are used by all camera manufacturers, each camera model has its own specifications when it comes to file sizes. Check the manual of your camera and find out the file size of each file format. Then, choose the file format that suits your artistic purposes and multiply the file size by the number of pictures you predict you’ll take in a photo session. The result will give you the capacity of the memory card you need.

Keep in mind that high resolutions and lossless file formats deliver the high-quality images required for print and editorials. So, don’t compromise on image quality.