Raw Photo Shoot Storage Calculator

Why RAW photos eat your memory card

A 24-megapixel camera can produce a JPEG of around 8 MB — and a RAW file of nearly 50 MB from the very same shot. The reason is simple: JPEG throws away most of the data the sensor captured, compressing and rounding it down to something small enough to share. RAW keeps it all — every level of brightness and colour — so you can fix exposure, white balance and shadows later without quality falling apart. That freedom is exactly why RAW files are huge, and why a memory card that comfortably holds 8,000 JPEGs might hold only 1,300 RAW files.

How the storage math works

A useful rule of thumb: one uncompressed RAW file takes about 2 MB per megapixel of your camera. Lossless compressed RAW trims that to about 1.25 MB per megapixel, and compressed (lossy) RAW to about 0.85 MB per megapixel. So each photo's size is your megapixel count times the rate for your RAW type — and if you record a JPEG copy alongside, add roughly 0.35 MB per megapixel for that. Multiply by the number of shots you expect, divide by 1,024 for gigabytes, and compare against your card. The calculator above does all of this and tells you whether the shoot fits, is tight, or needs a second card.

Worked example

Say you are shooting a 24-megapixel camera in uncompressed RAW, expecting 400 shots, with a 64 GB card. Each RAW file is 24 x 2.0 = 48.0 MB. For 400 shots that is 19,200 MB, or 18.75 GB — about 29.3% of the 64 GB card. The verdict is "fits easily": the card holds roughly 1,365 RAW photos at these settings, so you have plenty of room for extra bursts.

Practical tips

Always bring one more card than the math says you need — the best shot of the day often comes after your planned count. Format the card in the camera, not on a computer, before every shoot. If card space is tight, lossless compressed RAW keeps nearly all editing quality while saving about 40% of the space. And for fast action, remember the camera's buffer: a slow card can stall burst shooting even when the calculator says the shoot fits.