SMART IMAGE TOOLS IMAGE CALCULATOR

Image File Size Calculator.

Estimate raw pixel storage and understand the memory behind an image.

Your calculation

Calculated on your device

START WITH YOUR NUMBERS

Estimate the pixel data.

LIVE RESULT

The size behind the image.

6.22 MBuncompressed packed pixels

Binary size: 5.93 MiB
Exact total: 6,220,800 bytes
Pixels per image: 2,073,600 · 2.07 MP
8-bit RGBA buffer / image: 8.29 MB

Excludes headers, row padding, metadata and compression.

Meet an actual upload limit

Check your calculation

Check bit depth and image count.
Separate MB from MiB and packed data from RGBA memory.

Calculations stay on your device Works in your browser

METHOD & EXAMPLES

Know what goes into the result.

The uncompressed-size formula

Multiply width by height to count pixels, then multiply by total bits per pixel and divide by eight to get bytes. The estimate rounds up to a full byte for each image. Decimal MB uses 1,000,000 bytes; binary MiB uses 1,048,576 bytes.

bytes per image = ceil(width × height × bits per pixel ÷ 8)

Worked exampleA 1920 × 1080 RGB image at 24 bits per pixel needs 6,220,800 packed pixel bytes: 6.22 MB or about 5.93 MiB. An 8-bit RGBA buffer for the same dimensions needs 8,294,400 bytes.

Why a JPG or PNG file has a different size

Compressed formats depend on image detail, encoding settings and metadata. This estimate omits headers, row padding, compression and other file overhead. The separate RGBA figure models four 8-bit channels; browsers can need additional buffers, so it is not a total memory prediction. Use Compress to Size for an actual upload limit.

References

MDN: ImageData RGBA pixel storage (opens a new tab)

A PRACTICAL EXAMPLE

Know what a useful result looks like.

Estimate raw pixel storage without guessing compressed file size.

Try this workflow

Start with: A 1000 × 1000 image at 24 bits per pixel.
Set up: Set one image.
What to expect: Packed image data is 3,000,000 bytes: 3 MB or about 2.86 MiB. An 8-bit RGBA browser buffer for the same image uses 4,000,000 bytes.

Check before using the result

Check bit depth and image count.
Separate MB from MiB and packed data from RGBA memory.

When the result needs work

Headers, metadata, row padding, compression and extra working canvases are excluded. Measure the actual output when a website imposes a file limit.

Technical referencesMDN: decoded pixel data

Examples illustrate specific inputs and settings. Actual output size and appearance depend on your file and browser. Practice images are synthetic; they do not contain personal data.

GOOD TO KNOW

A few useful answers.

More help

Does this predict the size of a compressed JPG, PNG or WebP?

No. It estimates tightly packed uncompressed pixels. Compressed size depends on the image content, encoder and metadata. Use Image Information to see the actual size of a file.

What is the difference between 24-bit and 32-bit pixels?

A common 24-bit RGB layout has three 8-bit color channels. A 32-bit RGBA layout adds an 8-bit alpha channel. The selected value is total bits per pixel, not bits per channel.

Why does decoded memory exceed the file size?

A small compressed file can decode into millions of pixels. Four 8-bit RGBA channels require four bytes per pixel for one pixel buffer, and an editor can hold additional copies.

Is the calculation performed on a server?

No. These numeric calculations run in your browser. Shared links contain only the calculator settings; no image is required.