How Many Photos Fit on a Memory Card? Photos, Songs, and Video

Why a 64 GB card is not 64 GB

Two things eat into the number on the label. First, manufacturers count a gigabyte as one billion bytes, while many devices display capacity using binary gigabytes of 1,073,741,824 bytes, so a 64 GB card shows as about 59.6 GB. Second, the file system itself reserves some space for its index, trimming usable room a little further.

This is the same bits-and-bytes math behind the gap between advertised and real storage everywhere, from phones to hard drives. It is not a defect or false advertising; it is just two different definitions of the prefix giga meeting in one number. Knowing it explains why your brand-new card always seems slightly smaller than the box promised.

Average file sizes to use

Sizes vary with quality, but useful starting points are: a phone JPEG photo around 3 to 5 MB, a RAW photo from a camera 20 to 40 MB, a compressed song around 3 to 5 MB, and 1080p video roughly 100 MB per minute. 4K video is far heavier, often 300 to 500 MB per minute, which is why long 4K clips fill a card so fast.

The safest approach is to check the real size of a few of your own files rather than trusting a generic average, since your camera settings, subject, and format all move the number. Once you know your typical file size, the same division works for any card, and a storage capacity calculator lets you swap capacities and file sizes to compare options.

Working an example

Say you have a 128 GB card and shoot 6 MB JPEGs. Usable space is about 119 GB, or roughly 119,000 MB. Divide 119,000 by 6 and you get close to 19,800 photos. If you also record 1080p video at 100 MB per minute, every minute of footage costs the same room as about 17 photos, so a short film noticeably eats into that count.

This is why photographers often carry several smaller cards rather than one huge one: it spreads risk if a card fails and makes the math per card easy to track. Whatever mix you shoot, the single rule holds — usable capacity divided by average file size — and doing it before a trip stops you running out of space at the worst moment.

Frequently asked questions

Why does my card show less space than the label?

The label uses decimal gigabytes (a billion bytes each), while your device usually reports binary gigabytes that are about 7 percent larger, so the same card shows a smaller number. The file system also claims a little space for its own bookkeeping. Together these explain the gap, and neither is a fault with the card.

Do RAW photos really take that much more space?

Yes. A RAW file stores the sensor's full unprocessed data, so it is typically five to ten times larger than a JPEG of the same shot. A 5 MB JPEG might be a 30 MB RAW. RAW gives more editing latitude, but if you shoot RAW, expect a card to hold a fraction of the photos it would in JPEG.

How many hours of 4K video fit on 256 GB?

At a common 4K bitrate of around 100 Mbps, one hour of video is roughly 45 GB. So about 235 GB of usable space on a 256 GB card holds a little over 5 hours. Higher-bitrate cinema modes cut that time further, while more efficient codecs stretch it, which is why checking your camera's actual file sizes matters most.

Should I get one big card or several smaller ones?

Several smaller cards spread the risk: if one fails or is lost, you only lose part of your shoot rather than everything. One big card is more convenient and means fewer swaps, which suits casual use. For important events, many photographers prefer multiple mid-size cards so a single failure never wipes out the whole day.