Filestore Capacity Calculator
Size a Filestore instance against its tier minimum and capacity step, and see the throughput and IOPS you get.
Inputs
Zonal and regional Filestore scale throughput with provisioned capacity.
Monthly Cost
$1,135.20
Billed Capacity
3.00TiB
Billed Capacity in Bytes
3 TiB
Paid for but Not Needed
0.00TiB
Read Throughput
780MiB/s
IOPS
75,000IOPS
Throughput per Client
19.5MiB/s
Capacity Charge
$1,075.20
Step by step
Values used
Capacity you actually need = 3 TiB; Service tier = Zonal (1 TiB minimum, 256 GiB steps); Basic HDD price per GiB = 0.2000 USD/GiB-month; Basic SSD price per GiB = 0.3000 USD/GiB-month; Zonal price per GiB = 0.3500 USD/GiB-month; Regional price per GiB = 0.4500 USD/GiB-month; Read throughput per TiB = 260 MiB/s; IOPS per TiB = 25,000 IOPS; Backup data retained = 2,000 GiB; Backup price per GiB = 0.0300 USD/GiB-month; NFS clients mounting the share = 40 clients
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.
Monthly Cost
= 1,135.20
Billed Capacity
= 3.00 TiB
Billed Capacity in Bytes
= 3,298,534,883,328
Paid for but Not Needed
= 0.00 TiB
Read Throughput
= 780 MiB/s
IOPS
= 75,000 IOPS
How it works
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
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.