How to Use Compression Ratio Calculator
The Compression Ratio Calculator quickly evaluates how effective a compression run was — for a single file, a backup archive or an entire dataset.
- Enter the original size and pick a unit (B/KB/MB/GB/TB).
- Enter the compressed size and pick its unit.
- Read the result panel — N:1 ratio, percent space saved, absolute reduction and the raw byte values.
Formula & Theory - Compression Ratio Calculator
The Compression Ratio Calculator uses:
Compression ratio = original_bytes / compressed_bytes
Space saved (%) = (1 − compressed_bytes / original_bytes) × 100
Reduction = original_bytes − compressed_bytes| Symbol | Meaning |
|---|---|
| original_bytes | File size before compression (in bytes) |
| compressed_bytes | File size after compression (in bytes) |
| Ratio | How many times smaller the compressed file is |
Assumptions and Limits
The Compression Ratio Calculator assumes both sizes are reported in the same byte definition (binary KB = 1024). It does not consider archive metadata or padding, which can matter at very small file sizes.
Use Cases for Compression Ratio Calculator
- Algorithm benchmarking — Compare gzip vs zstd vs brotli on the same dataset.
- Backup planning — Estimate storage needs for nightly archives.
- CDN bandwidth — Justify Brotli/Gzip on origin assets.
- Database dumps — Track how dumps shrink over time.
- Media pipelines — Validate JPEG/WebP/AVIF transcoding gains.
Drop in two sizes and the Compression Ratio Calculator gives you a clean, easy-to-quote ratio and percentage.