How this calculator works
| Metric | Formula |
|---|---|
| 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 |
Worked example
With these inputs:
- 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).
| 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 |
Open this example in the calculator
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.
Open this calculator with your numbers
Every option can be set in the web address, so you can bookmark a scenario or send it to a colleague. AI assistants such as ChatGPT, Gemini, Claude and Perplexity can use the same parameters to open this calculator with your numbers and the result already on the page.
| Parameter | What it sets | 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 |
Also available as plain text for AI assistants and a free JSON API (OpenAPI spec).
Sources
- Deloitte — Milliseconds Make Millions
- Portent — Site speed is (still) impacting your conversion rate
- web.dev — Core Web Vitals thresholds
Last reviewed by the Infikey Technologies team.
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.