Website Speed ROI Calculator
Measure the business impact of faster page load times
Website Speed ROI
Calculate the business impact of improving your website's page load time.
Takes ~2 minutes. Based on industry benchmarks from Google and Akamai research.
Press Enter to start
What this calculator does
The Website Speed ROI calculator translates page-load improvements into revenue, using the published research linking speed to conversion. Enter your traffic, conversion rate, and order value; the model applies evidence-based uplift ranges to show what faster pages are worth.
It is the calculator to bring to the meeting where engineering time for performance work competes with feature work.
How it works
Answer a short set of questions — volumes, time, and costs you already track. The calculator runs a pure, versioned formula and presents conservative, moderate, and optimistic scenarios, a receipt-style ledger tracing every figure back to an input, and a multi-year NPV/IRR view. Each report lists its assumptions so reviewers can challenge them line by line. See the methodology for how the models work, or view a complete sample report.
Benchmarks you can defend
- A 0.1s mobile speed improvement drove retail conversions up 8.4% and travel conversions up 10.1% (37 brands, 30M sessions). Deloitte/Google, "Milliseconds Make Millions", 2020
- A 100ms delay can hurt conversions by up to 7%, and 53% of mobile visitors abandon pages that take longer than 3 seconds. Akamai/SOASTA State of Online Retail Performance, 2017
- Vodafone improved LCP 31% and saw 8% more sales; Rakuten 24 saw +53.4% revenue per visitor after Core Web Vitals work. Google web.dev case studies
Every constant used in-product is cited — the full source list, with caveats, is on the methodology page.
Frequently asked questions
Are the speed-to-revenue studies trustworthy?
They are the best available, but they are observational, not randomised — which is why this calculator presents "up to" ranges and three scenarios rather than a single multiplier. Notably, the famous "Amazon: 100ms = 1% of sales" figure has no verifiable methodology, so this product does not use it.
Which speed metric should I improve first?
The case studies with the clearest revenue links are Core Web Vitals improvements — particularly Largest Contentful Paint on mobile, where the Deloitte/Google research measured conversion effects from as little as 0.1s of improvement.
Is the Website Speed ROI calculator free?
Your first calculator is free forever, with unlimited re-runs and one saved report — no card required. You enter your email to view and save results, and upgrading to Pro unlocks all 13 calculators, unlimited reports, exports, and share links.
Can I change the assumptions?
Yes — every assumption is editable before you calculate, and the report records exactly what you used. Industry constants are cited on the methodology page, and the receipt-style ledger traces each figure in the result back to an input.