RAW photo file size calculator

It converts those two specifications into an approximate byte count, decimal megabytes, and binary mebibytes. The result is useful for storage planning, transfer estimates, and comparing camera workflows. It is a transparent mathematical estimate rather than a prediction of every proprietary RAW format, because actual files may use compression, metadata, padding, previews, or manufacturer-specific packing.

Enter the sensor resolution and stored bit depth

Start with the effective megapixel count used for the photograph, not necessarily the rounded marketing number printed on the camera body. A 24-megapixel input is interpreted as 24,000,000 sensor pixels. Then enter the number of uncompressed bits assigned to each pixel sample. Common camera values include 12, 14, and 16 bits, although the calculator accepts any finite positive value so it can cover unusual scientific and industrial sensors as well. The bit depth is not the same thing as the bits-per-channel label used for a finished RGB image. A typical Bayer-pattern camera sensor records one filtered sample at each photosite before demosaicing, so the simple estimate uses one sample per sensor pixel. Both fields are required. Megapixels must be greater than zero, since a zero or negative sensor resolution cannot represent a photograph, and bit depth must also be positive for the byte calculation to have physical meaning. Decimal values are accepted for cameras whose published effective resolution is, for example, 24.2 megapixels.

Understand the calculation and the reported units

The estimator multiplies megapixels by 1,000,000 to obtain the pixel count, multiplies that count by the selected bit depth, and divides by eight to convert bits into bytes. For example, each 16-bit sample consumes two uncompressed bytes, while a mathematically packed 12-bit sample consumes one and a half bytes on average. The output includes the estimated pixels and bytes so you can audit the calculation directly. It also gives decimal megabytes, where one MB equals 1,000,000 bytes, and binary mebibytes, where one MiB equals 1,048,576 bytes. Storage manufacturers and transfer-rate specifications often use decimal units, while operating systems and technical tools may display binary units, so the two values legitimately differ even though they describe the same byte total. Results are rounded only for stable, readable JSON output; the underlying formula does not add a compression factor, safety allowance, thumbnail size, or metadata estimate. This makes comparisons consistent across cameras and avoids disguising assumptions as measured facts.

Use the estimate for practical storage planning

Treat the result as a baseline for an uncompressed capture, then adapt it to the real workflow you are planning. Multiply the per-photo byte result by an expected frame count to estimate a shoot, burst, memory card, archive, or backup requirement. Allow additional room for filesystem overhead, catalog databases, sidecar files, previews, edits, and a sensible free-space margin. A camera's actual RAW files may be smaller when it uses lossless or lossy compression, or somewhat larger when samples are padded into 16-bit words, embedded previews are substantial, metadata is extensive, or extra pixels outside the nominal image area are retained. Multi-shot modes and some specialized sensors may store more than one sample per output pixel, which also falls outside this simple model. For the most accurate operational forecast, compare the estimate with several files produced by the exact camera, RAW mode, crop setting, and firmware version you will use. The calculator remains valuable as a format-independent reference and as a quick check when measured file sizes are unavailable.