Calculator Form
Example Data Table
| Asset | Original Size | Compressed Size | Ratio | Reduction | Resolution |
|---|---|---|---|---|---|
| Hero Banner | 8.00 MB | 2.40 MB | 3.33:1 | 70.00% | 3840 × 2160 |
| Product Photo | 4.50 MB | 1.35 MB | 3.33:1 | 70.00% | 3000 × 2000 |
| App Screenshot | 2.10 MB | 780 KB | 2.76:1 | 62.80% | 1440 × 2960 |
| Catalog Thumbnail | 900 KB | 210 KB | 4.29:1 | 76.67% | 800 × 800 |
Formula Used
Compression Ratio = Original File Size ÷ Compressed File Size
Reduction Percentage = ((Original File Size − Compressed File Size) ÷ Original File Size) × 100
Compressed Size Share = (Compressed File Size ÷ Original File Size) × 100
Theoretical Raw Size = Width × Height × (Bit Depth ÷ 8)
Effective Bits Per Pixel = (File Size in Bytes × 8) ÷ Total Pixels
Batch Storage Saved = (Original File Size − Compressed File Size) × Number of Images
Compression ratio shows how many times the original size exceeds the compressed size. A 4:1 result means the source needs four times more storage than the compressed file.
Reduction percentage explains storage decrease in percentage terms. It is useful when comparing export presets, optimization pipelines, and delivery targets across many image assets.
Effective bits per pixel helps judge compression density. Lower values usually mean stronger compression, while much lower values can indicate visible detail loss.
How to Use This Calculator
- Enter a project or batch name so exported CSV and PDF files remain easy to identify.
- Choose the image format you are reviewing, such as JPEG, PNG, WebP, AVIF, or another output type.
- Type the original file size and select its unit. Use the exact pre-optimization image size when possible.
- Type the compressed file size and select the correct unit for the optimized output.
- Enter image width, height, and bit depth to calculate theoretical raw size and effective bits per pixel.
- Add the number of images in the batch to estimate total storage demand and total storage savings.
- Press Calculate Ratio to display the result panel above the form, directly below the page header.
- Use the CSV and PDF buttons after calculation to download the computed metrics for reporting or comparison work.
Frequently Asked Questions
1. What does a 3:1 compression ratio mean?
It means the original image is three times larger than the compressed image. The optimized file needs one third of the original storage space.
2. Is a higher compression ratio always better?
No. A higher ratio saves more storage, but it can also reduce visible detail. The best ratio balances quality, speed, and file size goals.
3. Why do width, height, and bit depth matter?
They help estimate theoretical raw image size and effective bits per pixel. These values show how aggressively the file is compressed compared with pixel data.
4. Can this calculator handle batch planning?
Yes. Enter the number of images to estimate total original storage, total compressed storage, and total batch savings for campaigns or large libraries.
5. What if the compressed file is larger than the original?
The calculator marks that case as expanded. This can happen with unsuitable formats, light optimization, or when metadata increases total file size.
6. Which unit should I choose for file size?
Choose the unit that matches your measured file size. The calculator converts bytes, kilobytes, megabytes, and gigabytes automatically before computing results.
7. What is effective bits per pixel?
It is the stored number of bits per pixel after accounting for file size. It helps compare compression strength across images with different resolutions.
8. When should I export CSV or PDF?
Export CSV for spreadsheet comparison and bulk reporting. Export PDF when you need a quick shareable summary for reviews, approvals, or documentation.