Technical calculator
Docker Memory Calculator
Estimate usable host memory, planned container allocation, and container count from explicit reserves, headroom, overcommit, and per-container memory.
Calculated result
$0.00 monthly
$0.00 annually
Methodology and assumptions
Formula: Usable memory = (host memory − OS reserve − Docker/system reserve) × (1 − headroom). Planned allocation = usable memory × overcommit ratio. Container count = floor(planned allocation ÷ per-container allocation).
Worked example:A 64 GiB host with 4 GiB for the OS, 2 GiB for Docker/system services, 15% headroom, no overcommit, and 2 GiB per container yields 49.3 GiB usable and 24 theoretical containers.
Common mistake or edge case:This is a planning ceiling, not a guarantee. Measure application RSS and page cache; account for swap policy and host overhead. A container that exceeds Docker --memory can be killed by the OOM killer. Overcommit increases that risk.
Compare this host-level estimate with the Kubernetes resource calculator and pod capacity calculator. Docker --memory sets a hard memory limit; workload RSS, page cache, swap configuration, and OOM behavior still need production measurement.
Pricing last verified:
Official source: Docker Engine resource constraints documentation
Frequently Asked Questions
What does the Docker Memory Calculator calculate?
Estimate usable host memory, planned container allocation, and container count from explicit reserves, headroom, overcommit, and per-container memory.
How accurate is the Docker Memory Calculator?
It is a planning estimate based on the inputs, formula, assumptions, and sources shown on this page. Actual prices, invoices, taxes, discounts, and outcomes can differ.
Which pricing source does the Docker Memory Calculator use?
The calculator links to Docker Engine resource constraints documentation as its official source. The displayed pricing or reference data was last verified on 2026-09-14.
Are calculator inputs saved or sent to analytics?
Inputs are processed in your browser. Calculator values are not included in analytics events.