Image File Size Calculator
Estimate uncompressed image size from pixel dimensions and color depth.
Calculate pixels, megapixels and raw storage requirements before compression.
Browser-based calculation. Values stay in the current page. A selected file is read locally and is not uploaded by this tool.
PRACTICAL WORKFLOW NOTES
Estimate Raw Image Data Before Compression Changes the File
An imageās pixel dimensions tell you how many picture elements it contains, but they do not directly tell you the size of a JPEG, PNG, WebP, or TIFF file. Image File Size Calculator estimates the uncompressed image data from width, height, and color depth so you can understand the raw amount of pixel information before format compression, metadata, or container overhead changes the final file on disk. It is useful for imaging workflows, memory planning, scanning, print preparation, and comparing different resolutions.
The basic relationship is straightforward: width multiplied by height gives the number of pixels, and the selected bits per pixel determine how much raw storage those pixels require. A higher color depth or larger canvas increases the uncompressed total even if the subject of the image does not change. The calculator can also show megapixels, which is convenient for comparing camera or export resolutions. This raw estimate should not be confused with a compressed file size because image formats use very different encoding methods.
A photographic JPG may be much smaller than the raw estimate because lossy compression discards information that is less visible to the viewer. PNG is lossless and can vary widely depending on image complexity. WebP can use efficient lossy or lossless encoding. TIFF can also use different storage methods. Metadata, color profiles, thumbnails, and encoder settings add their own overhead. Use the raw number for memory and data-volume planning, then inspect the actual exported file when a website or delivery system has a strict file-size limit.
The calculation is performed locally in the browser and does not need an image upload when you enter dimensions manually. It provides a technical estimate, not a prediction of the exact compressed output from a specific application. DPI / Print Size Calculator is the better tool when physical print dimensions matter, while Aspect Ratio Calculator helps compare the shape of different pixel sizes. If the real goal is to make an existing image smaller, Image Compressor or Image Resizer changes the file rather than only estimating its data size. For imaging specifications, record width, height, color depth, and calculated raw bytes together because those inputs are what make a later estimate reproducible.
How to Use Image File Size Calculator
Use the live browser workflow below, then verify the final value against the requirement that matters for your task.
Enter pixel width
Add the image width in pixels.
Enter pixel height
Add the image height so the calculator can determine the total number of pixels.
Choose color depth
Use the bits-per-pixel value that matches the raw image representation you want to estimate.
Review pixels and megapixels
Check the total pixel count and megapixel figure alongside the storage estimate.
Compare with real file formats carefully
Treat the raw estimate as a baseline; JPG, PNG, WebP and other formats can be much smaller or different because of compression and metadata.
Separate Raw Pixel Data From the Size of a Compressed Image File
Use width, height and color depth to understand uncompressed image data before formats such as JPG, PNG or WebP apply compression and metadata.
Pixel count
Width multiplied by height gives the total number of pixels in the image.
Megapixels
Express the pixel count in millions for an easier comparison between image dimensions.
Color depth
Bits per pixel determine how much raw data is associated with each pixel in the estimate.
Uncompressed size
The calculator estimates raw pixel storage rather than predicting a specific compressed output file.
Compression changes size
Two images with identical dimensions can produce very different JPG, PNG or WebP sizes depending on content and settings.
Dimension follow-up
Use DPI / Print Size Calculator when the next question is physical print size rather than raw storage.
PRIVACY & RESPONSIBLE USE
Image Size Estimation Needs Only Dimensions and Color Depth
The raw-size calculation runs from numeric inputs in the browser and does not require the image to be uploaded.
See File Security & Processing and the Privacy Policy for broader site-level details.
No image upload required
Width, height and color depth are enough for the uncompressed storage estimate.
Raw, not compressed
The result does not promise the final size of a JPG, PNG, WebP or other compressed format.
Content affects compression
Image detail, transparency, noise, format choice and encoder settings can all change an actual file size.
COMMON QUESTIONS
Frequently Asked Questions
How is uncompressed image size estimated?
The calculator uses total pixels and the selected bits per pixel to estimate the raw amount of image data.
What is a megapixel?
One megapixel is approximately one million pixels. It describes image resolution, not the final compressed file size.
Why is my JPG much smaller than the raw estimate?
JPG uses compression, so its stored file size can be far below the uncompressed pixel-data size.
Can PNG or WebP have a different size from JPG at the same dimensions?
Yes. Compression method, transparency, image content and encoder settings can create very different files from the same pixel dimensions.
What does color depth change?
A higher bits-per-pixel value increases the amount of raw data associated with each pixel.
Does the tool predict exact compressed file size?
No. It estimates uncompressed image data rather than the final output of a particular codec.
Do I need to upload an image?
No. The calculation is based on numeric width, height and color-depth inputs.
How do I calculate print size from the same pixels?
Use DPI / Print Size Calculator to relate pixel dimensions to physical dimensions at a chosen DPI.