Image File Size Calculator
Estimate image file size from dimensions, bit depth and compression. Predict bytes before you export to meet upload limits and storage budgets. Private.
Estimate the raw or compressed file size of an image before you create it, so you can plan uploads and storage. Enter dimensions and format details, and the estimate updates instantly, all in your browser.
How it works
What this calculator does
Estimate the raw or compressed file size of an image before you create it, so you can plan uploads and storage. Enter dimensions and format details, and the estimate updates instantly, all in your browser.
Why the math matters
A reliable file size estimate helps you meet upload limits and storage budgets before you export.
Frequently asked questions
How do I estimate an image file size?
Multiply width by height by bit depth for the raw size, then adjust for the format. JPG and WebP compress heavily, while PNG keeps more data.
Why is my JPG much smaller than the raw estimate?
JPG is lossy, so it discards detail to shrink the file. The estimate for JPG reflects that compression, while the raw figure applies to uncompressed formats.
How accurate is the file size estimate?
It is close for a given quality and format. For an exact limit, run the target size compressor, which re-encodes until the file fits precisely.