06 OCTOBER 2026 · STORAGE · MEMORY-CARDS · GEAR
How Many RAW Photos Fit on a 128GB Card, by Body
A 45 megapixel Nikon Z8 and a 45 megapixel Canon EOS R5 capture the exact same number of pixels per frame, and still don’t fit the same number of photos on a card. The Z8’s lossless compressed RAW averages around 55MB. The R5’s averages around 45MB. On a 128GB card, that’s roughly 2,300 frames on one body and 2,800 on the other, a 20% swing that has nothing to do with resolution and everything to do with how each company’s RAW compression actually works.
“A 128GB card holds about 4,000 RAWs” is the kind of answer you’ll find everywhere, and it’s only true for one specific body at one specific resolution. Here’s the table that actually matters: what fits, by camera, at the card sizes you’re likely to own.
Megapixels set the pixel count. They don’t set the file size.
Every camera maker runs its own lossless (or near-lossless) compression on RAW files before they hit the card, and the algorithms don’t compress equally. A Sony RAW and a Nikon RAW at the same resolution routinely land 10-20% apart in size. Scene content moves the number too: a cluttered dance floor with hundreds of small high-frequency edges compresses worse than a clean portrait against open sky, because there’s more real detail for the algorithm to encode. The MB figures below are realistic averages across a mixed shoot, not a worst case or a best case.
RAW photos per card, by camera
| Body | Resolution | RAW size | 64GB | 128GB | 256GB | 1TB |
|---|---|---|---|---|---|---|
| Sony A7 III | 24 MP | ~25 MB | ~2,550 | ~5,100 | ~10,200 | ~40,000 |
| Sony A7 IV | 33 MP | ~35 MB | ~1,800 | ~3,600 | ~7,300 | ~28,500 |
| Canon EOS R5 | 45 MP | ~45 MB | ~1,400 | ~2,800 | ~5,700 | ~22,200 |
| Nikon Z8 | 45 MP | ~55 MB | ~1,150 | ~2,300 | ~4,650 | ~18,200 |
| Sony A7R V | 61 MP | ~62 MB | ~1,000 | ~2,050 | ~4,100 | ~16,100 |
Those numbers are straight arithmetic against the card’s labeled capacity. Shooting RAW+JPEG, or a different body entirely, changes the math - the storage calculator linked at the end of this post runs it for your exact camera and format, including every body in this table and a dozen more, directly in your browser.
Why the real count runs below the arithmetic
Two things eat into the table above before you’ve shot a single frame.
A labeled card never delivers its full label. A “128GB” card formats to roughly 119GB of usable space in-camera, because manufacturers count a gigabyte as 1,000,000,000 bytes while filesystems report it in binary units, and formatting itself reserves a slice for the file table. That’s about a 7% haircut off every number in the table above, on every card size, before content variance even enters the picture.
Average file size is an average, not a ceiling. A wedding with a packed reception floor and a lot of fairy lights will compress worse than a quiet portrait session on the same camera, which means a single real-world shoot can run meaningfully bigger than the per-frame average the table uses. Treat the table as the most you’ll fit, not a number you can plan against exactly - the same instinct behind leaving headroom on a drive instead of filling it to the last gigabyte.
Put together, a card that the arithmetic says holds 2,800 frames is more honestly a card you shouldn’t push past 2,400-2,500 on a real job. That’s not a flaw in the math; it’s the gap between a spec sheet and a Saturday.
How many cards a wedding day actually needs
A full wedding day runs 2,000 to 4,000 RAW frames for a single shooter, so the question isn’t “how many photos fit on a card” in the abstract - it’s whether that range fits on the cards you’re actually carrying.
On a 24 MP body, even a heavy 4,000-frame day comes in around 100GB, which fits inside a 128GB card’s real ~119GB with some room to spare. On a 45 MP Canon R5, a typical 2,500-frame day lands around 112GB - just inside a 128GB card, which is exactly why a long ceremony or an unusually trigger-happy day can run you out of space on a single card where it wouldn’t on a lighter body. On a 45 MP Z8, that same 2,500 frames runs closer to 137GB, already past what a 128GB card actually holds. And on a 61 MP A7R V, even the light end of the range - 2,000 frames - comes to about 124GB, more than a 128GB card can hold before you’ve shot a single formal portrait.
The practical read: a 24-33 MP body can usually get through a full day on one well-chosen 128GB card. A 45-61 MP body wants 256GB as the realistic minimum for a single card, or a second card to split the day across. That second part matters for another reason too - if you’re running dual cards in backup mode rather than overflow, each card needs to hold the whole day on its own, not half of it, since backup mode writes every frame to both slots at once.
None of this touches whether the card can keep up with your burst rate in the first place - that’s a write-speed question, not a capacity one, and it’s worth checking separately if you shoot fast continuous bursts; the V-rating printed on the card, not the capacity, is what prevents a camera from stalling mid-burst.
Buy the card for your camera, not the generic answer
“How many RAWs fit on a 128GB card” doesn’t have one answer, because the honest version of that question always has a camera model attached to it. A 24MP shooter and a 61MP shooter buying the same card are buying very different amounts of real shooting time, even though the box on the shelf says the same number. Run your actual body and your actual frame count through the photo storage calculator before your next card order, and you’ll know the real number instead of the one that happens to be true for someone else’s camera.
This kind of per-camera number is exactly what turns up occasionally in our field-notes emails, if that’s useful to have on hand before the next gear order rather than re-Googled every time.
Get new instruments first
The first one has the whole bench in it. After that, a short note when a new instrument lands or Gallery gets a real update - nothing else, and one click leaves.