Image File Size Calculator

Estimate uncompressed image memory usage for RGB, RGBA and grayscale workflows.

Image File Size Calculator

Estimate uncompressed image memory usage for RGB, RGBA and grayscale workflows.

How image memory size is calculated

Uncompressed image memory can be estimated from the number of pixels, the number of channels and the number of bits stored per channel. The basic formula is width × height × channels × bits per channel ÷ 8.

This is useful when planning RAM or GPU memory for large photographs, renders, textures, compositing work and image sequences.

RGB vs RGBA

RGB uses three channels: red, green and blue. RGBA adds a fourth alpha channel for transparency. For the same dimensions and bit depth, an RGBA image therefore requires one third more uncompressed memory than RGB.

8-bit, 16-bit and 32-bit

8-bit per channel is common for many finished images. 16-bit is widely used for higher-quality photo and compositing workflows, while 32-bit floating-point images are used in some HDR and visual-effects pipelines. Select the bit depth and channel count above to compare them instantly.

Common image resolutions

The presets include Full HD, QHD, 4K, camera-photo resolutions and square RGBA textures. Remember that this calculator estimates uncompressed memory. A JPEG, PNG or other compressed file on disk can be much smaller.

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