How much revenue is site speed costing you every month?

Slower pages convert worse, and the loss compounds across traffic you have already paid for. Answer five questions about your traffic and load time to see what closing that gap is worth.

How many sessions does your store get a month?

Total monthly sessions across all channels, from your analytics. For example, 15,000.

How this is calculated

Slower pages convert fewer visitors, and the relationship is well documented across independent studies of ecommerce load times. This tool models a conversion rate improving by roughly 7% for every second of load time you cut, up to 6 seconds of improvement. Beyond that range the relationship weakens, so the model caps there rather than extrapolating.

This is a directional estimate to size the opportunity, not a guaranteed outcome. Actual impact depends on your traffic quality, device mix, and what specifically is slowing the page down.

Measure your own load time

The calculator is only as good as the load time you feed it. Run your storefront through Google PageSpeed Insights and use the mobile Largest Contentful Paint it reports. Where field data is available it reflects real visitors rather than a lab run, which is the number worth modelling.

Sources

• Deloitte with Google, Milliseconds Make Millions
  Across 37 retail and travel brands, a 0.1 second mobile speed improvement lifted retail conversions 8.4% and average order value 9.2%. That is a steeper slope than this tool models, which is why the figure here is the more conservative one.
  deloitte.com, Milliseconds Make Millions
• Google, Core Web Vitals
  Defines the field metrics Google uses to judge page experience, including Largest Contentful Paint, the load-time measure this tool asks for.
  web.dev/articles/vitals
• Google, Largest Contentful Paint
  Sets the under 2.5 second target used as the default in step 3, measured at the 75th percentile of real page loads.
  web.dev/articles/lcp

Sources last checked August 2026.