Edge Performance Score Calculator

Score an edge delivery setup on cache efficiency, tail latency, reliability and protocol adoption, then rank the weakest.

About Edge Performance Score Calculator

Each pillar is normalised to 100 from a figure you can pull from CDN analytics, with cache and tail latency carrying the most weight because they dominate what users experience. Latency scores as a ratio rather than a subtraction, so a p95 at twice the target scores 50 regardless of the absolute numbers. A single score makes edge configuration comparable across properties and over time, and naming the weakest pillar turns it into one concrete action instead of a dashboard nobody acts on.

Formula

Edge Performance Score

score = cache × 0.30 + tail latency × 0.30 + reliability × 0.25 + protocol adoption × 0.15, where cache is scored against a 95% target and latency as target ÷ observed p95.

cache pillar: Byte hit ratio scored against a 95% practical ceiling
latency pillar: Latency target divided by the observed p95, capped at 100
reliability pillar: Error rate penalised at 20 points per percent, blended with availability

Worked example

With the default values below, Edge Performance Score Calculator returns Overall Edge Score of 77.7. Change any input above and every figure here is recalculated in your browser.

Inputs used

Byte cache hit ratioaccepts 0–100 %: 88 %
Observed p95 response timeaccepts 1–60,000 ms: 180 ms
p95 latency targetaccepts 1–60,000 ms: 100 ms
5xx error rate at the edgeaccepts 0–100 %: 0.4 %
Measured availabilityaccepts 90–100 %: 99.95 %
Handshakes resumed or 0-RTTaccepts 0–100 %: 65 %
Compressible responses actually compressedaccepts 0–100 %: 80 %
Traffic served over HTTP/3accepts 0–100 %: 45 %

Results

Overall Edge Score: 77.7 / 100
Grade: B — Good
Cache Efficiency Pillar: 92.6 / 100
Tail Latency Pillar: 55.6 / 100
Reliability Pillar: 93.8 / 100
Protocol Adoption Pillar: 65.0 / 100
Fix This First: Tail latency — move processing to the edge and shrink the largest responses

Step by step

1Values used
2Edge Performance Score
3Overall Edge Score= 77.7 / 100
4Grade= B — Good
5Cache Efficiency Pillar= 92.6 / 100
6Tail Latency Pillar= 55.6 / 100
7Reliability Pillar= 93.8 / 100
8Protocol Adoption Pillar= 65.0 / 100

Assumptions and limits

The result is derived only from the 8 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 is Edge Performance Score calculated?

score = cache × 0.30 + tail latency × 0.30 + reliability × 0.25 + protocol adoption × 0.15, where cache is scored against a 95% target and latency as target ÷ observed p95. Each pillar is normalised to 100 from a figure you can pull from CDN analytics, with cache and tail latency carrying the most weight because they dominate what users experience. Latency scores as a ratio rather than a subtraction, so a p95 at twice the target scores 50 regardless of the absolute numbers.

Why does Edge Performance Score matter?

A single score makes edge configuration comparable across properties and over time, and naming the weakest pillar turns it into one concrete action instead of a dashboard nobody acts on.

What values do I need to enter?

This calculator takes 8 inputs: Byte cache hit ratio, Observed p95 response time, p95 latency target, 5xx error rate at the edge, Measured availability, Handshakes resumed or 0-RTT, Compressible responses actually compressed, Traffic served over HTTP/3. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.