Memory Card Calculator

Estimate how many photos fit on an SD or CFexpress card from card capacity and average file size.

Inputs

Results

How card capacity is counted

Manufacturers usually advertise decimal gigabytes (1 GB = 1,000,000,000 bytes). Cameras and computers often show binary GiB, so a “128 GB” card may report closer to 119 GiB. This calculator uses decimal GB × 1000 for a practical photo count.

Typical file sizes

Use the photo file size calculator for a megapixel-based estimate.

FAQ

Should I leave free space on the card?

Yes. A small reserve (5–10%) avoids write errors when the card is nearly full and leaves room for buffer clearing on burst shooting.

Do video and stills share the same math?

Video is bitrate × time. Use the video file size calculator for recording length.

Workflow tips

Format cards in-camera, carry spares, and retire cards that show mount errors. The photo count here assumes average file size—you can raise the MB-per-frame input after reviewing a typical shoot folder for a tighter forecast.

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