EFS Storage Calculator
Cost an EFS file system across Standard, Infrequent Access and Archive tiers including the per-GB read charge.
Inputs
Monthly File System Cost
$685.20
Standard Tier Cost
$600.00
Cold Tier Storage Cost
$83.20
Cold-tier Access Cost
$2.00
Cost With No Lifecycle Policy
$2,400.00
Saving From Lifecycle Management
71.5%
Step by step
Values used
Data in the file system = 8,000 GB; Share in Standard = 25 %; Share in Infrequent Access = 55 %; Share in Archive = 20 %; Standard price = 0.3000 USD per GB-month; Infrequent Access price = 0.0160 USD per GB-month; Archive price = 0.0080 USD per GB-month; Data read from the cold tiers each month = 200 GB; Cold-tier access charge = 0.0100 USD per GB
EFS Storage
cost = Σ(tier share x GB x tier rate) + cold GB read x access charge, with the shares normalised to 100%.
Monthly File System Cost
= 685.20
Standard Tier Cost
= 600.00
Cold Tier Storage Cost
= 83.20
Cold-tier Access Cost
= 2.00
Cost With No Lifecycle Policy
= 2,400.00
Saving From Lifecycle Management
= 71.5
How it works
EFS Standard is an order of magnitude dearer per GB than Infrequent Access, but the cold tiers add a per-GB charge every time data is read back, so the saving only holds for files that are genuinely idle. Lifecycle management moves files after a configurable idle period, and a policy that is too aggressive turns a storage saving into a larger access bill. All rates here are user-supplied list prices to verify on the AWS EFS pricing page for your region. EFS is often the most expensive GB in an account, so knowing the cold-tier break-even in reads per month is what makes a lifecycle policy safe to enable on a shared home directory.
Formula
EFS Storage
cost = Σ(tier share x GB x tier rate) + cold GB read x access charge, with the shares normalised to 100%.
- tier share
- Portion of the file system resident in each tier
- access charge
- Per-GB fee for reading data out of IA or Archive
Frequently Asked Questions
How is EFS Storage calculated?
cost = Σ(tier share x GB x tier rate) + cold GB read x access charge, with the shares normalised to 100%. EFS Standard is an order of magnitude dearer per GB than Infrequent Access, but the cold tiers add a per-GB charge every time data is read back, so the saving only holds for files that are genuinely idle. Lifecycle management moves files after a configurable idle period, and a policy that is too aggressive turns a storage saving into a larger access bill. All rates here are user-supplied list prices to verify on the AWS EFS pricing page for your region.
Why does EFS Storage matter?
EFS is often the most expensive GB in an account, so knowing the cold-tier break-even in reads per month is what makes a lifecycle policy safe to enable on a shared home directory.
What values do I need to enter?
This calculator takes 9 inputs: Data in the file system, Share in Standard, Share in Infrequent Access, Share in Archive, Standard price, Infrequent Access price, Archive price, Data read from the cold tiers each month, Cold-tier access charge. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
How many reads make Infrequent Access more expensive?
Divide the monthly per-GB saving by the per-GB access charge. With a 0.284 USD saving and a 0.01 USD access fee, a GB can be read about 28 times a month before IA costs more than Standard.