User Quota Calculator

Work out user quota instantly with clear inputs, formula shown and shareable results.

About User Quota Calculator

Quotas are deliberately overcommitted because users rarely all fill their allocation at once — a 1.5 times factor means the sum of quotas exceeds capacity, which is fine until it is not. The soft quota triggers a warning and a grace period, and the hard quota is the absolute block, so the soft limit is what actually changes behaviour.

Formula

Quota sizing

allocatable = size x (1 - reserve); fair share = allocatable / users; hard quota = fair share x overcommit; soft = 0.8 x hard

Worked example

With the default values below, User Quota Calculator returns Hard quota per user of 10.20. Change any input above and every figure here is recalculated in your browser.

Inputs used

Users on the filesystemminimum 1: 500
Filesystem sizeminimum 0.001 GB: 4,000 GB
Reserve kept unallocatedaccepts 0–60 %: 15 %
Quota overcommit factoraccepts 1–10 x: 1.5 x

Results

Hard quota per user: 10.20 GB
Soft quota per user: 8.16 GB
Strict fair share per user: 6.80 GB
Allocated quota as a share of the filesystem: 128%

Step by step

1Values used
2Quota sizing
3Hard quota per user= 10.20 GB
4Soft quota per user= 8.16 GB
5Strict fair share per user= 6.80 GB
6Allocated quota as a share of the filesystem= 128

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 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

Is quota overcommitment safe?

It relies on usage being uneven. Monitor total actual usage against capacity rather than total allocated quota, and keep the reserve untouched.

What does the grace period do?

It allows a user to exceed the soft quota temporarily — typically seven days — after which the soft limit is enforced as if it were hard, forcing cleanup.