A Thousand Moments — Photo File-Size and Card Capacity Sample
https://www.athousandmoments.com/how-many-photos-can-a-memory-card-hold/
Worksheet updated November 1, 2026. Arithmetic estimates, not measured guarantees.

SETTINGS
Camera / firmware / card / slot:
Image area and size:
RAW compression / JPEG or HEIF quality:
One file, RAW+JPEG same card, split cards, mirror, or overflow?
Other files recorded / expected video workload:

SPACE INPUTS
Labeled or measured usable capacity / GB or GiB:
Already used space in same units:
If entering actual free space as capacity, used input is zero: [ ]
Chosen reserve percentage of remaining space / reason:
Reserve is a planning choice; it does not measure formatting overhead.

REPRESENTATIVE FILE SAMPLE
Scene types and settings:
Number of exposures sampled:
Total relevant file bytes / exposures:
Average bytes per exposure:
Largest observed relevant file group / bytes:
Primary file size / MB or MiB:
Companion JPEG size if on the same card / same file units:

ESTIMATES
Average-based additional exposures:
Larger-observed-size additional exposures:
Camera counter and actual settings:
Reason for mismatch or remaining uncertainty:
Spare cards / verified offload plan:
Existing files protected before any separate format decision: [ ]

1 GB = 1,000,000,000 bytes; 1 GiB = 1,073,741,824 bytes.
1 MB = 1,000,000 bytes; 1 MiB = 1,048,576 bytes.
Estimate = floor[(capacity-used bytes) * (1-reserve/100) / bytes per exposure].
This planner handles one card and still exposures, not video time or card speed.