How is buffer depth calculated?

Buffer depth in frames equals the buffer memory size divided by the file size per image. A 2GB buffer with 50MB RAW files holds 40 frames. The buffer clears continuously as data writes to the card, so actual burst depth can be slightly higher than this simple calculation.

Why does card speed matter for buffer?

While shooting, the camera simultaneously writes from buffer to card. A faster card drains the buffer quicker, effectively increasing your burst depth and reducing recovery time between bursts. This is especially important for sports, wildlife and event photography.

How do I find my camera buffer size?

Camera manufacturers rarely publish exact buffer sizes. Check your camera manual for rated burst depths at various file formats. You can estimate the buffer by multiplying the rated RAW burst depth by your RAW file size. Typical buffer sizes range from 1GB to 4GB in modern cameras.

What is sustained shooting rate?

Once the buffer fills, shooting continues at the sustained rate — determined by how fast the card can write. Sustained RAW fps = card write speed / RAW file size. A 90 MB/s card with 50MB files sustains only 1.8 fps, regardless of the camera burst rate.

PhotoCalcs

Buffer Calculator — Buffer Depth & Write Speed

Estimate buffer depth from file size, write speed and burst rate for RAW and JPEG shooting.

RAW File Size

Size of one RAW file

JPEG File Size

Size of one JPEG fine

Burst Rate

Continuous shooting speed

Buffer Size

Camera buffer memory

Card Type

Memory card write speed

How We Calculate This

This calculator estimates buffer performance based on file sizes and card write speed:

Buffer Depth

Frames = buffer size (MB) / file size (MB)

Burst Duration

Duration = buffer depth / burst rate

Sustained Rate

Sustained fps = card write speed / file size

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.