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Micro-Segmentation Calculator

Compare the worst-case n-squared policy count against your observed flows to size a micro-segmentation rollout.

About Micro-Segmentation Calculator

If every group could talk to every group, including itself, you would need groups² policies — 576 for 24 groups. Real estates are sparse: flow discovery typically shows well under a third of that mesh in use, so the achievable policy count is observed flows times the rules each flow needs, plus one intra-group allow per group. The n² figure is why micro-segmentation projects fail when driven from architecture diagrams; the gap between n² and observed flows is exactly the lateral movement you remove, and it is also the risk register for what you might break.

Formula

Micro-Segmentation

worst case policies = workload groups²; real policies = observed flows × rules per flow + one intra-group rule per group.

workload groups
Distinct labels or tiers you write policy against
observed flows
Group-to-group conversations actually seen in flow logs

Worked example

With the default values below, Micro-Segmentation Calculator returns Policy Rules Required of 384. Change any input above and every figure here is recalculated in your browser.

Inputs used

Workload groups (labels / tiers)accepts 1–1,000 groups
24 groups
Distinct group-to-group flows observedaccepts 0–1,000,000 flows
180 flows
Policy rules per allowed flowaccepts 1–16 rules
2 rules
Total workloads to enforce onaccepts 1–1,000,000 workloads
900 workloads

Results

Policy Rules Required
384
Worst-Case Policy Count (n²)
576
Inter-Group Pairs
552
Flow Density vs Full Mesh
31.25%
Lateral Paths Removed
68.75%
Policy Rules per Workload
0.427

Step by step

  1. 1Values used
  2. 2Micro-Segmentation
  3. 3Policy Rules Required= 384
  4. 4Worst-Case Policy Count (n²)= 576
  5. 5Inter-Group Pairs= 552
  6. 6Flow Density vs Full Mesh= 31.25
  7. 7Lateral Paths Removed= 68.75
  8. 8Policy Rules per Workload= 0.427

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 or compounding frequency into account.
  • Figures are rounded for display to 3 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 Micro-Segmentation calculated?

worst case policies = workload groups²; real policies = observed flows × rules per flow + one intra-group rule per group. If every group could talk to every group, including itself, you would need groups² policies — 576 for 24 groups. Real estates are sparse: flow discovery typically shows well under a third of that mesh in use, so the achievable policy count is observed flows times the rules each flow needs, plus one intra-group allow per group.

Why does Micro-Segmentation matter?

The n² figure is why micro-segmentation projects fail when driven from architecture diagrams; the gap between n² and observed flows is exactly the lateral movement you remove, and it is also the risk register for what you might break.

What values do I need to enter?

This calculator takes 4 inputs: Workload groups (labels / tiers), Distinct group-to-group flows observed, Policy rules per allowed flow, Total workloads to enforce on. 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 long should I run in observe-only mode first?

At least one full business cycle — 30 days is the common floor — so that month-end batch jobs, backup windows, quarterly reporting and DR tests all appear in the flow data. Enforcing on two weeks of observation is the classic way to break a monthly finance close.

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