Camera Storage & File Size Calculator
Estimate what percentage of a memory card a session will fill based on your camera's megapixels and number of photos (RAW files assumed). Use it to plan card capacity before a shoot.
Last updated: September 2026
Formula below · 1 source (Wikipedia) · Updated Sep 2026
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About this calculator
The formula calculates storage usage as a percentage of card capacity: usagePercent = (megapixels × 1.2 MB × photosPerSession) / (cardGB × 1,000 MB) × 100. It assumes RAW files of about 1.2 MB per megapixel — a 24 MP camera's compressed RAW file is roughly 25–30 MB — which is the safe assumption for planning cards. JPEGs are typically 3–4× smaller (about 0.3–0.4 MB per megapixel), so a JPEG-only shoot uses roughly a quarter to a third of the figure shown. Understanding storage requirements before a shoot prevents running out of space at a critical moment and helps determine how many cards or how large a card you need.
How to use
Suppose you have a 24 MP camera shooting RAW, you plan to take 500 photos per session, and your memory card holds 32 GB (32,000 MB). Step 1: File size ≈ 24 × 1.2 = 28.8 MB. Step 2: Session total = 28.8 × 500 = 14,400 MB. Step 3: 14,400 / 32,000 × 100 = 45%. Your session will use about 45% of the card, so a 32 GB card is sufficient with room to spare; shooting JPEG only, it would be closer to 12–15%.
Frequently asked questions
How much storage does a RAW photo from a 24 megapixel camera actually use?
A RAW file from a 24 MP camera typically ranges from 24 MB to 35 MB per file, depending on the camera manufacturer's compression algorithm and scene complexity. Canon CR3 and Nikon NEF files from 24 MP sensors average around 25–28 MB uncompressed. Losslessly compressed RAW formats (like Sony ARW or Fujifilm RAF) can reduce this to 18–22 MB without any quality loss. In contrast, a high-quality JPEG from the same camera averages 8–12 MB. If you shoot RAW+JPEG simultaneously, you use both file sizes for every frame, roughly tripling your storage consumption compared to JPEG-only. Always budget generously: use a storage calculator as a minimum estimate and carry at least one backup card.
What memory card capacity do I need for a full-day wedding photography shoot?
A full-day wedding typically involves 8–10 hours of shooting and 1,500–3,000 exposures from the primary photographer. At 24 MP RAW (approximately 28 MB per file), 2,000 photos requires about 56 GB of storage. Professional wedding photographers typically carry multiple cards — often two or three 64 GB cards — both for capacity and redundancy in case of card failure. Many modern cameras support dual card slots for simultaneous backup, which effectively doubles storage consumption but protects against catastrophic loss. It is best practice to never fill a card completely; stop at 80–90% to avoid write errors and ensure buffer space.
Does shooting in RAW versus JPEG significantly affect how many photos fit on a memory card?
Yes, significantly. A 24 MP RAW file is typically 3–5 times larger than a JPEG of the same image. On a 64 GB card, you might fit roughly 2,200 RAW files but over 7,000 high-quality JPEGs. The trade-off is image editing flexibility: RAW files contain all the data captured by the sensor, allowing full recovery of highlights, shadows, white balance, and colour profiles in post-processing. JPEGs apply in-camera processing and compression that permanently discards data. Most professional photographers shoot RAW for important assignments and JPEG for casual sessions or high-volume sports work. If storage is limited, some cameras offer medium or small RAW sizes that reduce file size by 30–40% with minimal quality impact at typical print sizes.