Filestore Capacity Calculator
Size a Filestore instance against its tier minimum and capacity step, and see the throughput and IOPS you get.
About Filestore Capacity Calculator
Filestore performance is a function of provisioned capacity, so the only way to buy more throughput or IOPS is to buy more TiB — and every tier has a minimum plus a step size that rounds your request upward. That means a 1.1 TiB requirement on a 256 GiB step is billed at 1.25 TiB. Because throughput scales with size, teams frequently over-provision Filestore for performance and then treat the spare capacity as waste, when the honest framing is that they are paying for MiB/s. Confirm the per-GiB price for your tier and region in the Google Cloud pricing calculator, as regional costs noticeably more than zonal.
Formula
Filestore Capacity
billed capacity = max(tier minimum, requested rounded up to the capacity step); throughput = billed TiB × MiB/s per TiB; cost = billed GiB × tier price + backup GiB × backup price.
- tier minimum
- 1 TiB for Basic HDD, Zonal and Regional; 2.5 TiB for Basic SSD
- capacity step
- 256 GiB on Zonal and Regional, so capacity snaps upward
- MiB/s per TiB
- Performance that scales with provisioned capacity rather than being bought separately
Worked example
With the default values below, Filestore Capacity Calculator returns Monthly Cost of $1,135.20. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Capacity you actually needaccepts 0.1–1,000 TiB
- 3 TiB
- Service tierone of Basic HDD (1 TiB minimum), Basic SSD (2.5 TiB minimum), Zonal (1 TiB minimum, 256 GiB steps), Regional (1 TiB minimum, 256 GiB steps)
- Zonal (1 TiB minimum, 256 GiB steps)
- Basic HDD price per GiBaccepts 0–10 USD/GiB-month
- 0.2 USD/GiB-month
- Basic SSD price per GiBaccepts 0–10 USD/GiB-month
- 0.3 USD/GiB-month
- Zonal price per GiBaccepts 0–10 USD/GiB-month
- 0.35 USD/GiB-month
- Regional price per GiBaccepts 0–10 USD/GiB-month
- 0.45 USD/GiB-month
- Read throughput per TiBaccepts 1–5,000 MiB/s
- 260 MiB/s
- IOPS per TiBaccepts 100–200,000 IOPS
- 25,000 IOPS
- Backup data retainedaccepts 0–1,000,000 GiB
- 2,000 GiB
- Backup price per GiBaccepts 0–10 USD/GiB-month
- 0.03 USD/GiB-month
- NFS clients mounting the shareaccepts 1–100,000 clients
- 40 clients
Results
- Monthly Cost
- $1,135.20
- Billed Capacity
- 3.00 TiB
- Billed Capacity in Bytes
- 3 TiB
- Paid for but Not Needed
- 0.00 TiB
- Read Throughput
- 780 MiB/s
- IOPS
- 75,000 IOPS
- Throughput per Client
- 19.5 MiB/s
- Capacity Charge
- $1,075.20
Step by step
- 1Values used
- 2Filestore Capacity
- 3Monthly Cost= 1,135.20
- 4Billed Capacity= 3.00 TiB
- 5Billed Capacity in Bytes= 3,298,534,883,328
- 6Paid for but Not Needed= 0.00 TiB
- 7Read Throughput= 780 MiB/s
- 8IOPS= 75,000 IOPS
Assumptions and limits
- The result is derived only from the 11 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Filestore Capacity calculated?
billed capacity = max(tier minimum, requested rounded up to the capacity step); throughput = billed TiB × MiB/s per TiB; cost = billed GiB × tier price + backup GiB × backup price. Filestore performance is a function of provisioned capacity, so the only way to buy more throughput or IOPS is to buy more TiB — and every tier has a minimum plus a step size that rounds your request upward. That means a 1.1 TiB requirement on a 256 GiB step is billed at 1.25 TiB.
Why does Filestore Capacity matter?
Because throughput scales with size, teams frequently over-provision Filestore for performance and then treat the spare capacity as waste, when the honest framing is that they are paying for MiB/s. Confirm the per-GiB price for your tier and region in the Google Cloud pricing calculator, as regional costs noticeably more than zonal.
What values do I need to enter?
This calculator takes 11 inputs: Capacity you actually need, Service tier, Basic HDD price per GiB, Basic SSD price per GiB, Zonal price per GiB, Regional price per GiB, Read throughput per TiB, IOPS per TiB, Backup data retained, Backup price per GiB, NFS clients mounting the share. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Can I shrink a Filestore instance later?
No. Capacity can be increased in place but not reduced, so the safe pattern is to start near the tier minimum and grow, rather than provisioning for a year of forecast growth on day one.