Skip to main content

Find your next tool

DashboardAndroid app
Language
Appearance

Image planning & checks

Image File Size Calculator

Plan the raw storage for an image or a batch of scans. Read an actual image, enter pixels, or work from paper size and scanning resolution; compare the measured file bytes separately.

Calculate on your device

JPG, PNG or WebP, up to 25 MiB / 40 megapixels. Read locally; no upload.

Enter your own scenario, for example 25 for one-quarter of the raw bytes. This does not predict a JPEG or PDF encoder.

Enter valid values to see the calculation. Results update as you type.

Calculations and image inspection run in this browser. Continuing to another tool saves a temporary local copy. No account is needed.

What this helps you do

  • Compare a paper scan scenario with raw pixel storage in MB and MiB.
  • Read a real image’s dimensions and encoded byte count, keeping those measurements separate from assumptions.

When to use it

  • Estimate raw storage for a batch of equal-sized scanned pages.
  • Compare grayscale and color scanning before selecting an export workflow.

How to use this calculator

  1. Enter pixels, read an image, or enable Plan a scan from paper dimensions and choose a paper size and DPI.
  2. Choose the pixel storage depth and number of equal-sized pages or frames. Optionally enter your own encoded-size percentage as a scenario.
  3. Read the raw bytes and assumptions. For an inspected image, continue to transfer planning using its actual encoded size.

Raw pixel storage is different from download size

The calculation multiplies width, height and bits per pixel, divides by eight to convert bits to bytes, then multiplies by image count. RGB with 8 bits per channel uses 24 bits per pixel; RGBA adds an alpha channel for a total of 32.

A JPEG, PNG or WebP file is encoded. Its size depends on image detail, metadata, compression and encoder settings. Two images with identical dimensions can have very different download sizes. Use the actual encoded file to check an upload limit.

For a paper scan, each dimension in millimeters is divided by 25.4 and multiplied by DPI, then rounded up to a whole pixel. Doubling both dimensions through a higher scanning resolution produces four times as many pixels. For batches, this estimates only equally sized raw images. An editor may retain an original, a preview and several intermediate copies. Treat the result as pixel-data storage, not a promise that a browser can process the whole batch in that much RAM.

Formats, privacy and limits

  • Local inspection accepts JPG, PNG and WebP up to 25 MiB, 10,000 pixels per side and 40 megapixels. Scan scenarios use equal-sized pages.
  • The model excludes file headers, row padding, OCR text, metadata and application memory. An optional encoded-size percentage is your assumption, not a predicted JPEG or PDF size.
  • Handoffs use a temporary local copy with a 30-minute one-use token. Use the actual exported file to check a destination upload limit.

Common questions

Can this predict a JPEG file size?

No. Dimensions and bit depth are not enough to predict encoded JPEG size. Compress or export the actual image and read the resulting file’s byte count.

Why does adding alpha increase raw storage?

An 8-bit alpha channel adds one byte per pixel to 8-bit RGB data. That changes 24 bits per pixel to 32 bits per pixel.

Does this include headers and row padding?

No. The estimate packs pixel data into whole bytes per image. File headers, row alignment, metadata and application allocations are additional.

Put the result to work

Inspect an actual image →

Read real dimensions and encoded file size.

Reduce encoded file size →

Prepare a smaller file for an upload limit.

Check an upload limit →

Test the actual exported bytes against the destination limit.