Page Speed Score Calculator

Combine Core Web Vitals into a single weighted page speed score with a grade.

About Page Speed Score Calculator

Each dimension is scored out of 100 and combined using its normalised weight, so the result stays on a 0-100 scale. The weakest dimension is surfaced separately because a good average routinely hides one failing area. A single page speed number is what gets reported upward, but the weakest-dimension line is what tells you where the next hour of work should go.

Formula

Page Speed Score

Score = Σ (dimension × weight), weights normalised to 1

dimension: Each contributing measure, scored 0-100
weight: Relative importance of that dimension

Worked example

With the default values below, Page Speed Score Calculator returns Score of 80.6. Change any input above and every figure here is recalculated in your browser.

Inputs used

Largest Contentful Paint scoreaccepts 0–100 %: 78 %
Interaction to Next Paint scoreaccepts 0–100 %: 85 %
Cumulative Layout Shift scoreaccepts 0–100 %: 92 %
First Contentful Paint scoreaccepts 0–100 %: 80 %
Time to First Byte scoreaccepts 0–100 %: 70 %

Results

Score: 80.6 /100
Rating: B — Good
Weakest Dimension: Time to First Byte score
Points to the Next Grade: 9.5
Risk Band: Informational

Step by step

1Values used
2Page Speed Score
3Score= 80.6 /100
4Rating= B — Good
5Weakest Dimension= Time to First Byte score
6Points to the Next Grade= 9.5
7Risk Band= Informational

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, 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 Page Speed Score calculated?

Score = Σ (dimension × weight), weights normalised to 1 Each dimension is scored out of 100 and combined using its normalised weight, so the result stays on a 0-100 scale. The weakest dimension is surfaced separately because a good average routinely hides one failing area.

Why does Page Speed Score matter?

A single page speed number is what gets reported upward, but the weakest-dimension line is what tells you where the next hour of work should go.

What values do I need to enter?

This calculator takes 5 inputs: Largest Contentful Paint score, Interaction to Next Paint score, Cumulative Layout Shift score, First Contentful Paint score, Time to First Byte score. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.