Skip to content
ENExplore Calculators

Disk Throughput Requirement Calculator

Work out disk throughput requirement instantly with clear inputs, formula shown and shareable results.

About Disk Throughput Requirement Calculator

Throughput is IOPS multiplied by I/O size, so the two cloud volume limits interact: 8,000 IOPS at 32 KB needs 250 MB/s, which is exactly a common gp3 baseline cap. Larger I/O sizes hit the throughput cap before the IOPS cap, which is why the same volume that serves a database happily may throttle a backup job.

Formula

Throughput from IOPS

throughput MB/s = IOPS x I/O size KB / 1024; compare against the volume throughput cap

Worked example

With the default values below, Disk Throughput Requirement Calculator returns Throughput required of 250.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

IOPS requiredminimum 0.001 IOPS
8,000 IOPS
Average I/O sizeaccepts 0.5–1,024 KB
32 KB
Share of I/O that is sequentialaccepts 0–100 %
40 %
Volume throughput limitminimum 0.001 MB/s
250 MB/s

Results

Throughput required
250.0 MB/s
Share of the volume throughput cap used
100.0%
Effective I/O size after sequential merging
38.4 KB
Binding limit
Throughput cap - the volume cannot deliver these IOPS at this I/O size

Step by step

  1. 1Values used
  2. 2Throughput from IOPS
  3. 3Throughput required= 250.0 MB/s
  4. 4Share of the volume throughput cap used= 100.0
  5. 5Effective I/O size after sequential merging= 38.4 KB
  6. 6Binding limit= Throughput cap - the volume cannot deliver these IOPS at this I/O size

Assumptions and limits

  • The result is derived only from the 4 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 1 decimal place, 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

Why does my volume throttle below its IOPS rating?

Because the throughput cap was reached first. Cloud volumes enforce both limits independently, and large I/O sizes reach the throughput cap at a fraction of the rated IOPS.

Does I/O size affect cost?

Indirectly. Some providers count I/O above a threshold as multiple operations, so 256 KB requests consume several IOPS each against the provisioned figure.

Related Calculators

Disk Throughput Requirement Calculator | Calcrivo