Why can I store fewer photos than expected?

Memory cards are marketed using decimal GB (1 GB = 1,000,000,000 bytes) but cameras and computers use binary GB (1 GB = 1,073,741,824 bytes). This means a 64GB card has about 59.6 GB of usable space — roughly 93% of the advertised capacity. This calculator accounts for this difference.

Does video resolution affect storage?

Resolution affects storage through bitrate. 4K at 100 Mbps uses about 750 MB per minute. 1080p at 50 Mbps uses about 375 MB per minute. Higher-quality codecs (ProRes, RAW video) use much higher bitrates — ProRes 4K can use 1-3 Gbps.

How many RAW photos fit on a 64GB card?

It depends on your camera sensor. A 24MP camera produces ~25MB RAW files (~2,400 photos). A 45MP camera produces ~50MB RAW files (~1,200 photos). A 61MP camera produces ~70MB RAW files (~860 photos). Compressed RAW reduces file sizes by 20-40%.

Should I use one large card or multiple smaller cards?

Professional photographers often prefer multiple smaller cards to reduce risk — if one card fails, you only lose part of the shoot. However, for video, larger cards avoid interrupted recordings. Many pros use dual card slots with backup mirroring for critical work.

PhotoCalcs

Memory Card Calculator — Photo & Video Capacity

Calculate how many photos or minutes of video fit on your memory card based on file sizes and video bitrate.

Card Size

Advertised card capacity

RAW File Size

Size of one RAW file

JPEG File Size

Size of one JPEG fine

Video Bitrate

Video recording bitrate

How We Calculate This

This calculator estimates storage capacity accounting for formatting overhead:

Usable Capacity

Usable GB = advertised GB x 0.93

Photo Count

Photos = usable MB / file size per photo

Video Duration

Minutes = (usable MB) / (bitrate Mbps / 8) / 60

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard optical and photographic formulas. Results may vary with specific equipment.