What is slow costing you?
Put in your visitors, your conversion rate and what a customer is worth. The calculator turns "the site feels slow" into a rand figure per month — using your numbers, with the assumption on show so you can argue with it.
How much is your load time costing?
Estimates only, and only as good as the numbers you put in. It exists to turn a vague worry into something you can weigh against the cost of fixing it.
From Google Analytics, or your best estimate.
Visitors who buy or enquire. 1–3% is typical.
What one converted visitor is worth to you.
Don't know? Measure it on PageSpeed Insights
Under 2.5 seconds is the usual goal on mobile.
Only used to build the PageSpeed link above.
The assumption this rests on
Industry studies land somewhere around 7% per second. Change it to whatever you believe — the result updates.
The working: —
This is an estimate built on a rule of thumb, not a measurement of your business. Speed is one of several things that decide whether a visitor converts — if the page is fast but the offer is unclear, fixing speed alone will not produce this number.
Why does a second make any difference?
Because waiting is where people decide you are not worth the effort. Nobody consciously abandons a site over two seconds — they just get bored, hit back, and take the next result instead. On South African mobile data that happens far more than it does on your office fibre.
Most of your traffic is mobile
Often on data, often away from a signal. The speed you experience in the office is not the speed most of your visitors get.
It affects being found too
Core Web Vitals feed into how Google ranks pages, so a slow site loses twice — fewer visitors, and fewer of them staying.
It's usually cheap to fix
Oversized images, too many plugins and slow hosting account for most of it. None of that needs a rebuild.
What actually makes a site slow?
Four things, in roughly this order: images straight off a camera, a pile of plugins, cheap shared hosting, and a theme doing far more than your site needs. The first is the most common and the easiest to fix.
Oversized images
A 4MB photo displayed at 600px wide. Compressing and sizing images properly often halves load time on its own.
Plugin sprawl
Every plugin adds scripts to every page, including the ones it is not needed on. Most sites are carrying several they no longer use.
Slow hosting
Shared hosting where hundreds of sites compete for the same machine. It shows up as a delay before anything appears at all. Managed hosting
A theme doing too much
Multipurpose themes load sliders, animations and fonts you never asked for. Sometimes the honest fix is a rebuild. Web design
Questions about the calculator.
It is a rule of thumb drawn from published industry research on load time and conversion, not a measurement of your business. That is exactly why it sits in an open field you can change — put in a figure you trust and the answer updates. If you think the effect is smaller, set it to 3% and see whether the number still justifies the work.
Treat it as an order of magnitude, not a forecast. It tells you whether you are arguing about hundreds a month or tens of thousands, which is usually the decision you actually need to make. Speed is one factor among several, and the calculator says so rather than pretending otherwise.
Because a straight line stops being believable at the extremes. Going from twenty seconds to two would not multiply your conversion rate by two and a half in reality, so the calculation only counts the first five seconds of difference. Without that cap the tool would produce numbers nobody should act on.
Put your address in the optional field above and use the PageSpeed Insights link — it opens Google's own test with your site loaded. Use the mobile figure rather than desktop, since that is what most of your visitors get. The number to look at is Largest Contentful Paint.
No. It all runs in your browser and disappears when you close the tab. There is no email field for the same reason there is none on the Scorecard tool — a tool people can use freely is worth more than a few reluctant email addresses.
Find out what is actually slowing the site down before spending anything. The free audit measures your speed properly and names the specific causes, so you are fixing the real problem rather than the first one somebody suggests.
Find out what's actually slowing it down.
The calculator estimates what speed is worth. The audit measures your real numbers and tells you which specific things are causing it — free, within 48 hours.