Sizing
Wetsuit size finderYour size in every brand Shoe size converterUK, US, EU and cm Bike frame calculatorRoad, mountain and hybrid
Swimming
Wetsuit thickness guideWhat to wear by water temp CSS calculatorCritical Swim Speed and zones Swim pace converterPool to open water, m and yd
Running
Race pace plannerSplits for your goal time Race time predictor5K to marathon from one result Hill effort converterGrade-adjusted pace Heart rate zonesFive zones, %max or Karvonen

Privacy policy

The short version: the calculators run in your browser, there is nothing to sign up for, and we do not sell your data.

Last updated 7 July 2026.

The numbers you type stay with you

Every tool on this site does its maths in your own browser. When you enter a height, a weight, a time or a pace, that number is used on your device to work out the result and is never sent to us or stored on a server. Close the tab and it is gone. There are no accounts, and we never ask for your name, email or payment details to use a tool.

What our host records

Like almost every website, our hosting provider keeps basic technical logs when a page is requested. These can include your device's IP address, the browser and device type, and which page was loaded. This is standard information used to keep the site secure and running, and it is not used to identify you personally.

Cookies

The site does not set advertising or tracking cookies of its own. If we later add privacy-friendly, aggregated visitor analytics to understand which tools are popular, we will update this page to say so and explain how to opt out.

Search engines

We use tools such as Google Search Console and Bing Webmaster Tools to see how the site appears in search results. These report anonymous, grouped data about searches and clicks. They do not tell us who you are.

Links to other sites

Some pages link to other websites, including retailers. Once you follow a link you are on their site, under their privacy policy, not ours. If a link is an affiliate link, meaning we may earn a small commission on a purchase at no extra cost to you, it will be marked on the page. We recommend checking the privacy policy of any site you buy from.

Children

These are general sport tools with no sign-up and no data collection, so they are safe for anyone to use, but the site is not aimed at children and we do not knowingly gather any information about them.

Your rights

Because we do not build a profile on you or store the numbers you enter, there is no personal account or dataset for us to show, change or delete.

Changes to this policy

If the way the site handles data changes, for example if analytics are added, we will update this page and change the date at the top.

More information

For the rules on using the site, see our terms of use.