# Image Compression Savings Calculator

> See how much bandwidth, money and load time compressing an image saves, from the original and compressed sizes and how often the image is loaded.

Category: Software, cloud & AI · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/image-compression-savings-calculator

Every byte you remove from an image is saved on every load. Multiply the saving per image by monthly loads to get the transfer saved, then price it.

Also called: Image optimisation savings calculator.

## Inputs
- File sizes in (options: kB (1,000 bytes), KiB (1,024 bytes); default kB)
- Original size (default 500)
- Compressed size (default 150)
- Image loads per month (default 1000000)
- Bandwidth price per GB (default 0.08; optional)
- Visitor connection speed (unit Mbps; default 10; optional)
- Currency

## Results
- Transfer saved per month
- Transfer saved per month
- Bytes saved per load
- Size reduction
- Bandwidth cost saved per month
- Download time saved per load

## Formula

```
Bytes saved = (Original − Compressed) × 1,000 (or 1,024);  GB saved = Bytes saved × Loads ÷ 10⁹;  Time saved = Bytes saved × 8 ÷ (Mbps × 10⁶)
```

Where:
- Loads: downloads of the image per month
- Mbps: connection speed in megabits per second (8 bits per byte)

## Worked example
1. Saved per load: 500 − 150 = 350 kB = 350,000 bytes (70%).
2. Per month: 350,000 × 1,000,000 = 3.5 × 10¹¹ bytes = 350 GB; × 0.08 = 28.
3. Time: 350,000 × 8 = 2.8 million bits ÷ 10 Mbps = 0.28 s = 280 ms.

**Result:** Cutting a 500 kB image to 150 kB saves 350 GB a month at a million loads, and about 280 ms per load on a 10 Mbps connection.

## What the result means

Bandwidth savings matter at scale, but the load-time saving usually matters more: smaller hero images improve Largest Contentful Paint, which affects user experience and search visibility.

## Assumptions and limits
- Every load transfers the whole file.
- Time saved assumes the connection is the bottleneck, ignoring latency.
- HTTP compression, caching and responsive image sizes mean real savings vary by visitor.

## Questions

### Why are bits and bytes mixed here?

File sizes are in bytes, but connection speeds are quoted in bits per second. One byte is 8 bits, so a 10 Mbps line moves 1.25 MB per second at best.

### Which formats compress best?

For photos, AVIF and WebP are usually much smaller than JPEG at similar visual quality; measure with your own images.

## Related calculators
- [CDN Bandwidth Cost Calculator](https://calculators.geekmidst.com/calculators/cdn-bandwidth-cost-calculator)
- [Data Transfer Time Calculator](https://calculators.geekmidst.com/calculators/data-transfer-time-calculator)
- [Percentage Change Calculator](https://calculators.geekmidst.com/calculators/percentage-change-calculator)

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/image-compression-savings-calculator