Swap Size Calculator
Get a recommended Linux swap partition size based on installed RAM and whether hibernation support is needed.
Inputs
Hibernation requires swap large enough to hold the entire RAM image
Recommended Swap Size
8.00GB
Standard Recommendation (no hibernate)
8.00GB
Hibernation-Safe Recommendation
10.83GB
Rule Applied
2GB < RAM ≤ 8GB → equal to RAM
Step by step
Values used
Installed RAM = 8 GB; Support Hibernation (suspend-to-disk) = No
Swap for RAM ≤ 2GB
swap = 2 × RAM
Swap for 2GB < RAM ≤ 8GB
swap = RAM
Swap for RAM > 8GB
swap = max(4, √RAM)
Hibernation-safe swap
swap = RAM + √RAM
Recommended Swap Size
= 8.00 GB
Standard Recommendation (no hibernate)
= 8.00 GB
Hibernation-Safe Recommendation
= 10.83 GB
Rule Applied
= 2GB < RAM ≤ 8GB → equal to RAM
How it works
Swap sizing guidance varies with installed RAM. Small-memory systems (≤2GB) benefit from swap double their RAM because the OS itself needs breathing room. Mid-size systems (2-8GB) do well with swap equal to RAM. Large-memory systems (>8GB) rarely need swap proportional to RAM, so the recommendation flattens to the larger of 4GB or the square root of RAM. If hibernation (suspend-to-disk) is required, swap must be at least RAM plus a safety margin (approximated here as RAM + √RAM) since the entire RAM image is written to swap on suspend.
Formulas
Swap for RAM ≤ 2GB
swap = 2 × RAM
- R
- installed RAM in GB
Swap for 2GB < RAM ≤ 8GB
swap = RAM
- R
- installed RAM in GB
Swap for RAM > 8GB
swap = max(4, √RAM)
- R
- installed RAM in GB
Hibernation-safe swap
swap = RAM + √RAM
- R
- installed RAM in GB
Frequently Asked Questions
Do I need swap if I have a lot of RAM?
Some swap is still useful even with abundant RAM — it lets the kernel move rarely-used pages out of RAM and provides a safety margin against out-of-memory situations, but it no longer needs to scale linearly with RAM.
Why does hibernation need more swap?
Hibernation writes the entire contents of RAM to swap before powering off, so the swap space must be at least as large as RAM, with a small margin for kernel bookkeeping — approximated here as RAM plus its square root.
Is swap on an SSD bad for the drive's lifespan?
Modern SSDs tolerate swap well under normal desktop/server workloads; the practical concern is more about performance (swapping is much slower than RAM) than SSD wear for typical usage patterns.