Mobile Page Speed Calculator

Estimate mobile load time accounting for slower CPU and network conditions.

About Mobile Page Speed Calculator

Mobile penalties compound: a slower CPU multiplies JavaScript execution while a slower network multiplies transfer. JavaScript-heavy pages suffer far more on mobile than image-heavy ones. Google indexes and ranks on mobile performance, so the mobile figure is the one that affects search visibility.

Formula

Mobile Page Speed

Mobile time = CPU portion × throttle factor + network portion × bandwidth ratio

CPU throttle: Mid-range mobile CPUs are roughly four times slower than desktop

Worked example

With the default values below, Mobile Page Speed Calculator returns Estimated Mobile Load Time of 9.428. Change any input above and every figure here is recalculated in your browser.

Inputs used

Desktop load timeminimum 0 s: 1.8 s
Mobile CPU slowdown factoraccepts 1–10 x: 4 x
Mobile connection speedminimum 0.01 Mbps: 8 Mbps
Desktop connection speedminimum 0.01 Mbps: 50 Mbps
Share of load time spent on JavaScriptaccepts 0–100 %: 45 %

Results

Estimated Mobile Load Time: 9.428 s
Slowdown Against Desktop: 5.238 x
Network-Bound Component: 6.188 s
CPU-Bound Component: 3.240 s
Rating: Poor

Step by step

1Values used
2Mobile Page Speed
3Estimated Mobile Load Time= 9.428 s
4Slowdown Against Desktop= 5.238 x
5Network-Bound Component= 6.188 s
6CPU-Bound Component= 3.240 s
7Rating= Poor

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 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 Mobile Page Speed calculated?

Mobile time = CPU portion × throttle factor + network portion × bandwidth ratio Mobile penalties compound: a slower CPU multiplies JavaScript execution while a slower network multiplies transfer. JavaScript-heavy pages suffer far more on mobile than image-heavy ones.

Why does Mobile Page Speed matter?

Google indexes and ranks on mobile performance, so the mobile figure is the one that affects search visibility.

What values do I need to enter?

This calculator takes 5 inputs: Desktop load time, Mobile CPU slowdown factor, Mobile connection speed, Desktop connection speed, Share of load time spent on JavaScript. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.