# Page speed revenue calculator: what a slow website costs in lost sales

> A slow website loses sales because conversion rates fall as load time rises. Deloitte found a 0.1-second mobile speed improvement went with 8.4% more retail conversions, and Portent found e-commerce sites loading in 1 second convert 2.5 times better than sites loading in 5 seconds. To estimate your gain, apply a conversion change for each second saved to your current conversion rate, then multiply the extra conversions by your order or lead value.

- Interactive version: https://infikeytechnologies.com/tools/page-speed-revenue-calculator
- Type: free instant calculator
- Category: Website performance & design
- Last reviewed: 2026-10-05
- Publisher: Infikey Technologies (https://infikeytechnologies.com)

## Example result (default inputs)

| Input | Value |
| --- | --- |
| Currency | USD ($) |
| Visits per month | 50,000 |
| Current conversion rate | 2% |
| Average order or lead value | 80 |
| Current load time | 4.5 seconds |
| Target load time | 2 seconds |
| Conversion loss per extra second | 7% |

**Extra revenue per year: $190,970.** Cutting load time from 4.5 to 2 seconds could add about 199 conversions and $15,914 a month ($190,970 a year).

A 2-second target meets Google’s “good” LCP threshold (2.5 s), which also supports search rankings through Core Web Vitals.

| Metric | Value |
| --- | --- |
| Seconds saved | 2.5 s |
| Conversion rate today | 2% |
| Conversion rate at target | 2.4% |
| Extra conversions per month | 199 |
| Extra revenue per month | $15,914 |
| Revenue lost per month by each extra second | $5,600 |

### Monthly revenue by load time

| Item | Value | Detail |
| --- | --- | --- |
| 1 s | $103,133 | 2.58% conversion |
| 2 s | $95,914 | 2.4% conversion |
| 3 s | $89,200 | 2.23% conversion |
| 4 s | $82,956 | 2.07% conversion |
| 5 s | $77,149 | 1.93% conversion |
| 6 s | $71,749 | 1.79% conversion |
| 8 s | $62,056 | 1.55% conversion |
| Today (4.5 s) (selected) | $80,000 |  |

- Studies compare many sites, and faster sites often differ in other ways too, so the default here is deliberately lower than published figures. Compare before and after a speed project, or A/B test, to confirm the effect on your own site.

Open this result on the website: https://infikeytechnologies.com/tools/page-speed-revenue-calculator?currency=USD&visitors=50000&conversion=2&value=80&current_time=4.5&target_time=2&loss_per_second=7

## Use from a link or API

Add these query parameters to https://infikeytechnologies.com/tools/page-speed-revenue-calculator (pre-filled page), https://infikeytechnologies.com/tools/page-speed-revenue-calculator.md (this plain-text page) or https://infikeytechnologies.com/api/tools/page-speed-revenue-calculator (JSON).

| Parameter | Meaning | Accepted values |
| --- | --- | --- |
| `currency` | Currency | one of USD, INR, AED, GBP, EUR |
| `visitors` | Visits per month | number from 1 to 10000000000, default 50000 |
| `conversion` | Current conversion rate | number from 0.01 to 100 (%), default 2 |
| `value` | Average order or lead value | number from 0 to 10000000 (in the chosen currency), default 80 |
| `current_time` | Current load time | number from 0.3 to 30 (seconds), default 4.5 |
| `target_time` | Target load time | number from 0.3 to 30 (seconds), default 2 |
| `loss_per_second` | Conversion loss per extra second | number from 0 to 50 (%), default 7 |

- Online store: https://infikeytechnologies.com/tools/page-speed-revenue-calculator?currency=USD&visitors=100000&conversion=1.8&value=70&current_time=4.5&target_time=2&loss_per_second=7
- B2B lead generation: https://infikeytechnologies.com/tools/page-speed-revenue-calculator?currency=USD&visitors=15000&conversion=2.5&value=400&current_time=5&target_time=2.5&loss_per_second=7
- Large retailer: https://infikeytechnologies.com/tools/page-speed-revenue-calculator?currency=USD&visitors=2000000&conversion=2.5&value=90&current_time=3.2&target_time=1.8&loss_per_second=7

## How it is calculated

- **Conversion rate at target**: current rate ÷ (1 − loss per second)^(seconds saved)
- **Extra conversions**: visits × (new rate − current rate)
- **Extra revenue**: extra conversions × order or lead value

## Core Web Vitals thresholds

| Metric | Measures | Good | Poor |
| --- | --- | --- | --- |
| Largest Contentful Paint (LCP) | Loading — when the main content appears | ≤ 2.5 s | > 4 s |
| Interaction to Next Paint (INP) | Responsiveness to clicks and taps | ≤ 200 ms | > 500 ms |
| Cumulative Layout Shift (CLS) | Visual stability while loading | ≤ 0.1 | > 0.25 |

## The quickest ways to speed up a website

- Compress and resize images; use WebP or AVIF and lazy-load images below the fold.
- Serve the site through a CDN with caching.
- Remove unused JavaScript, plugins and third-party tags; defer the rest.
- Preload the main image and web fonts; limit font weights.
- Use server-side caching and a fast host close to your visitors.

## FAQ

### How much does page speed affect conversions?

Deloitte’s Milliseconds Make Millions study found a 0.1-second mobile speed improvement went with 8.4% more retail conversions and 10.1% more travel conversions. Portent found e-commerce conversion rates averaged 3.05% at 1 second but 0.67% at 4 seconds. The effect varies by site, so test on your own.

### What is a good page load time?

Aim for the main content to appear within 2.5 seconds on mobile — Google’s “good” threshold for Largest Contentful Paint.

### Does page speed affect SEO?

Yes. Core Web Vitals are part of Google’s page experience signals. Speed rarely outranks relevance, but it can decide close competitions and it affects every visitor.

### How do I measure my website speed?

Use Google PageSpeed Insights or Search Console for real-user Core Web Vitals, and Lighthouse or WebPageTest for lab tests.

## Sources

- [Deloitte — Milliseconds Make Millions](https://www.deloitte.com/ie/en/services/consulting/research/milliseconds-make-millions.html)
- [Portent — Site speed is (still) impacting your conversion rate](https://www.portent.com/blog/analytics/research-site-speed-hurting-everyones-revenue.htm)
- [web.dev — Core Web Vitals thresholds](https://web.dev/articles/vitals)

## Get expert help

Send these results to an Infikey Technologies specialist from the form on https://infikeytechnologies.com/tools/page-speed-revenue-calculator#estimate or via https://infikeytechnologies.com/contact.

More free calculators: https://infikeytechnologies.com/tools.md

## Disclaimer

This calculator is provided free for general information and planning only. Results are estimates based on the inputs you enter and the assumptions described on this page, reference data such as published prices may change, and actual costs and outcomes will differ. Nothing on this page is financial, legal, tax, investment or other professional advice. Infikey Technologies Private Limited, Infikey Technologies LLC and their directors, employees and affiliates make no warranty, express or implied, about the accuracy, completeness or suitability of this tool or its results, and accept no liability for any loss or damage, direct or indirect, arising from its use or from reliance on its results. Verify all figures independently and seek professional advice before making any decision. Use of this tool is at your own risk.