VPN Health Score Calculator
Grade a VPN tunnel out of 100 using uptime, rekey failures, latency, loss and delivered throughput.
About VPN Health Score Calculator
Uptime dominates because a tunnel that flaps is worse than a slow one, and repeated rekey failures are the classic symptom of mismatched lifetimes or proposals between peers. The remaining weight is split across the performance metrics users actually feel. Tunnel dashboards show up or down; this turns the softer signals — rekey churn, MTU-driven loss, throughput shortfall — into a trend you can act on before the tunnel drops.
Formula
VPN Health Score
score = 0.3 × uptime + 0.2 × rekey stability + 0.2 × latency + 0.15 × loss + 0.15 × throughput sub-scores.
- uptime sub-score
- Linear from 0 at 95% availability to 100 at 100%
- rekey stability
- 100 minus 12 points per failed IKE or child SA rekey
Worked example
With the default values below, VPN Health Score Calculator returns VPN Health Score of 81.2. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Tunnel uptime over the periodaccepts 0–100 %
- 99.4 %
- Failed rekeys in the periodaccepts 0–500 events
- 2 events
- Tunnel round-trip latencyaccepts 0–2,000 ms
- 60 ms
- Packet loss inside the tunnelaccepts 0–50 %
- 0.3 %
- Delivered share of expected throughputaccepts 0–100 %
- 88 %
Results
- VPN Health Score
- 81.2 /100
- Grade
- B — Good
- Uptime Sub-score
- 88.0 /100
- Rekey Stability Sub-score
- 76.0 /100
- Suggested Action
- No action needed
Step by step
- 1Values used
- 2VPN Health Score
- 3VPN Health Score= 81.2 /100
- 4Grade= B — Good
- 5Uptime Sub-score= 88.0 /100
- 6Rekey Stability Sub-score= 76.0 /100
- 7Suggested Action= No action needed
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or fees or charges 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 is VPN Health Score calculated?
score = 0.3 × uptime + 0.2 × rekey stability + 0.2 × latency + 0.15 × loss + 0.15 × throughput sub-scores. Uptime dominates because a tunnel that flaps is worse than a slow one, and repeated rekey failures are the classic symptom of mismatched lifetimes or proposals between peers. The remaining weight is split across the performance metrics users actually feel.
Why does VPN Health Score matter?
Tunnel dashboards show up or down; this turns the softer signals — rekey churn, MTU-driven loss, throughput shortfall — into a trend you can act on before the tunnel drops.
What values do I need to enter?
This calculator takes 5 inputs: Tunnel uptime over the period, Failed rekeys in the period, Tunnel round-trip latency, Packet loss inside the tunnel, Delivered share of expected throughput. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.