Image File Size Calculator

Estimate an uncompressed image's storage size.

How the Math Works

The Image File Size Calculator uses a fundamental formula to determine the memory footprint of an image in its raw, uncompressed form. By multiplying the image's width and height in pixels, we get the total number of pixels. Multiplying this by the bit depth (bits per pixel) gives the total number of bits required to store the image. We then divide by 8 to convert bits to bytes, and finally divide by 1,048,576 (which is 1024 x 1024) to convert bytes to megabytes. This calculation reveals the true storage demands of high-resolution images before any compression is applied.

Practical Applications

To use this calculator, simply enter the width and height of your image in pixels, along with the bit depth your image uses. Standard images typically use 24 bits (8 bits each for red, green, and blue color channels) or 32 bits (24 bits for color plus 8 bits for transparency). Once you input these three values, the calculator instantly shows you the uncompressed file size in megabytes. This helps you estimate storage requirements before processing images or making design decisions about resolution and quality.

Day-to-Day Use

Understanding uncompressed image file sizes helps you make informed decisions about your digital life. When planning storage needs for photos, videos, or graphic design projects, knowing the true size of high-resolution images prevents storage surprises. It helps you choose appropriate image formats and compression levels for websites, social media, or email attachments. Whether you're a photographer managing a large photo library, a designer selecting the right resolution for print versus web, or simply trying to understand why some image files are enormous, this calculator provides valuable insights into digital media storage requirements.

Worked example

6000×4000 at 24-bit → ~68.7 MB uncompressed.

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