SEO & Web

Page Speed Revenue Impact Calculator

Speed work is easy to justify once you attach a revenue number to it. This models the saved seconds against an assumed conversion lift per second so you can put a figure next to the engineering ticket.

Your numbers

A relative lift assumption. Published estimates commonly cluster around 5 to 10 percent per second.

Result

Projected conversion rate2.52%
Seconds saved2.10 sec
Additional monthly conversions220
Additional annual conversions2,639

FormulaProjected rate = current rate × (1 + lift per second × seconds saved). Additional conversions = visitors × (projected rate - current rate)

Worked example

Cutting load from 4.2 to 2.1 seconds saves 2.1 seconds. At a 7 percent relative lift per second, a 2.2 percent conversion rate becomes 2.52 percent. Across 68,000 monthly visitors that is about 218 additional conversions a month, roughly 2,619 a year.

What to watch for

The lift per second figure is an assumption, not a measurement. Published studies cluster in a wide band and vary enormously by industry and starting speed, so treat the output as a business case input and then verify with your own before-and-after data.

Gains are not linear. Going from 8 seconds to 4 is transformative, going from 2 to 1 is often invisible to users and still worth doing for Core Web Vitals. This linear model overstates the value of the last second.

Measure at the 75th percentile on real user data, not on a lab test from a fast laptop. The mobile user on a mediocre connection is the one you are losing, and lab metrics never show them.

Frequently asked questions

How much does one second really cost?

Nobody can give you a universal figure honestly. The published estimates vary by industry, device, and starting point. Use this model to size the opportunity and then prove it with your own instrumented before-and-after.

Which speed metric should I optimize?

Largest Contentful Paint and Interaction to Next Paint carry the most weight for both users and Core Web Vitals. Time to first byte matters mostly as an upstream cause of a bad LCP.

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