Attack Surface Score
Free Attack Surface Score calculator with clear step-by-step results.
About Attack Surface Score
Attack surface grows with exposed assets, ports, privileges and legacy systems.
Formula
Formula
Score = weighted sum of exposed elements
Worked example
With the default values below, Attack Surface Score returns Attack Surface Score of 8.8. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Internet-facing assetsminimum 0
- 50
- Open portsminimum 0
- 120
- Users with admin accessminimum 0
- 5
- Legacy systemsminimum 0
- 8
Results
- Attack Surface Score
- 8.8
- Surface Band
- Large
- Contributors
- Facing 50 · Ports 120 · Admins 5 · Legacy 8
Step by step
- 1Values used
- 2Formula
- 3Attack Surface Score= 8.8
- 4Surface Band= Large
- 5Contributors= Facing 50 · Ports 120 · Admins 5 · Legacy 8
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
How does this calculator work?
Attack surface grows with exposed assets, ports, privileges and legacy systems.
Why does this matter?
A heuristic — smaller surfaces are generally easier to defend.