Docker Image Size Estimator
Enter layer sizes and planning assumptions to compare a rough Docker image footprint locally.
A QUICK WALKTHROUGH
How to use this tool
- Enter the base and layer sizes.
- Adjust extra layers, cache overhead and compression savings.
- Review the estimated uncompressed and compressed sizes.
Planning formula
Layer total = base + app + dependencies. Estimated before compression = (layer total + extra layers × average layer size) × (1 + cache overhead). Estimated after savings = before compression × (1 − compression savings). Because no layer sizes are supplied for extra layers, this tool uses the average of the three entered layer sizes as a transparent assumption.
Scope
This is a manual planning estimate. It does not connect to Docker, inspect an image, read a registry, or measure an actual push or pull.
GOOD TO KNOW
Common questions
Does this measure a real Docker image?
No. It is a planning estimate; use docker image inspect, build output, or registry measurements for actual size.
What does compression savings mean?
It is the percentage you expect to remove from the planning total. Registry compression, layer deduplication and transfer behavior vary by image and registry.
Can it guide multi-stage builds?
Yes, as a rough comparison if you enter only the runtime layers that would remain in the final stage.