Data Compression Ratio Calculator

Summary

Enter original and compressed file sizes to instantly compute compression ratio, space savings percentage, and bits per symbol.

How it works

1. Enter the original (uncompressed) file size and select the unit (bytes, KB, MB, or GB).
2. Enter the compressed file size and select its unit.
3. Optionally enter the number of symbols (characters or source bytes) for bits-per-symbol output.
4. Click Calculate to see the compression ratio, space savings, and efficiency metrics.
5. Use the reset button to clear all fields and start over.

Use cases

• Evaluate how effective a compression algorithm is on a specific dataset.
• Compare gzip, brotli, zstd, or other codecs on the same input.
• Calculate bits-per-symbol for information-theory assignments.
• Audit backup storage savings before and after compression.
• Quickly verify compression benchmarks when choosing a file format.

Frequently Asked Questions