An honest calculator: how much your slow website costs you every month

There are two types of loss in your business: the one you see and the one you don't. A customer who walks into your store and leaves, you notice. A customer who opens your website, waits 4 seconds, and closes it before it loads, you never find out.

But the second type is measurable, and it's usually bigger than the first for a business that depends on the internet.

The 3 numbers you need

To calculate your monthly loss from poor speed, I need 3 inputs:

1. Monthly visits to your site: you can see this in Google Analytics, in the WordPress dashboard, or in any tool you use. Don't have it? Estimate based on the average for your segment (local small businesses usually get between 500 and 5,000 visits per month).
2. Current conversion rate: out of every 100 visits, how many become contact or sale? Average for US small businesses: 2%.
3. Average ticket per customer: how much a customer pays on average per purchase or service.

The loss formula

Research from Google and Adobe shows two repeatable numbers:

• 47% of visitors abandon sites that take more than 3 seconds to load. That number rises to 90% if it goes past 5 seconds.
• Optimized sites convert 50% more than slow sites with the same content and same traffic.

So, if your site is slow (over 3 seconds on mobile), you lose 47% of visits before they even see anything. And of the ones that remain, you convert 50% less.

Practical calculation

Let's plug in numbers:

• Monthly visits: 1,000
• Current conversion (with slow site): 2%
• Average ticket: $200
• Current revenue: 1,000 × 2% × $200 = $4,000/month

If we optimize:

• Visits that load (don't give up): keep 1,000 (because good speed doesn't lose the 47%)
• Optimized conversion: 3% (50% higher)
• Average ticket: same $200
• Potential revenue: 1,000 × 3% × $200 = $6,000/month

Difference: $2,000/month lost due to poor speed. Over 12 months, that's $24,000 left on the table.

Why speed breaks so much

3 objective reasons:

1. Impatient customer. Mobile, bad internet, on the go. Did it load? No? Next competitor.
2. Google penalizes. Since 2021, Core Web Vitals have been a ranking factor. Slow site = shows up less = fewer visits to begin with.
3. Perception of professionalism. A site that takes long to load gives off an amateur business image. 5 seconds of waiting is an emotional filter against you.

"How do I know if my site is slow?"

Objective 30-second test: go to pagespeed.web.dev, paste your URL, wait. Then you get 2 scores (mobile and desktop) from 0 to 100.

• Above 80: fast site. You're good.
• Between 50 and 80: average. Could improve but not terrible.
• Below 50: slow. You're losing customers every day.

The mobile score is what matters most, since 70%+ of traffic for local small businesses comes from phones.

Summary

Do the math with your real numbers. If your estimated monthly loss from poor speed is greater than the cost of rebuilding the site, the decision becomes math. It's not about "wanting a new site", it's about stopping the silent loss of money.