Memory Card Photo Calculator
How many photos fit on your SD card? RAW and JPEG counts by card size and camera megapixels.
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How Card Capacity Is Calculated
The core formula is simple: average file size × number of photos = storage required. The tool estimates file size from the camera megapixel count and chosen format, then divides the card capacity by that per-photo size to estimate how many shots fit.
Format makes a dramatic difference. An uncompressed RAW file — the unprocessed data straight off the sensor — runs roughly megapixels × 1.05 MB (a 24 MP RAW is about 25 MB; losslessly compressed RAW is roughly 60 percent of that). A fine-quality JPEG, compressed and processed in-camera, runs closer to megapixels × 0.3 MB. That is a 3 to 5 times difference: a 128 GB card holds roughly 4,800 RAW files from a 24 MP body but around 16,000 JPEGs from the same camera. Photographers who shoot RAW for maximum post-processing flexibility need proportionally larger or more numerous cards than those shooting JPEG only.
What You Should Know
- File size is not fixed even within one format — it depends on scene content. High ISO noise and fine detail, such as foliage, texture or gravel, compress less efficiently and produce larger files; clean, simple scenes such as sky or studio backdrops compress smaller. Budget storage using an average estimate, not a best-case minimum.
- Video storage uses a completely different formula — not a fixed per-frame file size, but bitrate (Mbps) × duration. A 100 Mbps 4K video recorded for 10 minutes consumes roughly 100 ÷ 8 × 600 = 7,500 MB, about 7.3 GB, regardless of megapixels. See the dedicated video size calculator for that math.
- Splitting capacity across several mid-size cards limits the worst-case loss if one card fails or is lost, compared to trusting everything to a single large card. Dual card-slot cameras that mirror or split recording across two cards offer the strongest protection.
- For video work, prioritize the card sustained write speed class (V30, V60, V90, and so on) over raw capacity — a large card that cannot sustain the required bitrate will drop frames or stop recording.
Frequently Asked Questions
Why do my file sizes vary shot to shot?
Compression depends on content: high-ISO noise and fine detail (foliage) inflate files, clean skies shrink them. Budget with the average, not the minimum.
One big card or several small ones?
Several mid-size cards limit worst-case loss if a card fails, and dual-slot backup beats both. For video, prioritize sustained-write speed class over capacity.
How much bigger are RAW files than JPEGs, exactly?
Roughly 3 to 5 times bigger for the same shot, depending on compression settings. An uncompressed RAW from a 24 MP camera runs about 25 MB, while a fine JPEG from the same sensor is closer to 7 MB. Lossless-compressed RAW narrows the gap to about 2 to 3 times, since it is roughly 60 percent of the uncompressed RAW size.
Why is video storage calculated differently from photos?
Photos are discrete files with a size tied to resolution and compression, so multiplying file size by photo count works directly. Video is a continuous stream recorded over time, so its storage depends on bitrate, meaning how much data is captured per second, multiplied by duration, not on megapixels or frame count alone — a 4K video at a low bitrate can take less space than 1080p at a high bitrate.
Should I buy one large card or several smaller ones?
Several mid-capacity cards limit how much work is lost if a single card fails, gets corrupted, or is misplaced — only the shots on that one card are at risk, not the whole shoot. A single large card is more convenient day to day, but professional workflows on important shoots, such as weddings or commercial jobs, typically favor multiple cards or dual-slot backup for exactly this reason.
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