Ian Welkins

I'm an independent web developer based in Houston, Texas, and I build free, single-purpose calculator websites. Each site in the fleet takes one narrow subject — a craft, a sport, a household job — and builds the best set of tools it can for that one subject, instead of spreading thin across everything. Swim Pace Calculator is the swimming member of that fleet: ten pace calculators and a reference chart, and nothing that is not about pace.

The pattern is the same on every site I run. The tools are free, with no accounts and no sign-up. The formulas and data come from published sources — governing bodies, standards documents, peer-reviewed research and official event guides — and those sources are named on the page that uses them, so any reader can go to the same document and check the same figure. The method is not a trade secret kept in a help centre; it is printed next to the calculator it describes. I research the sources, write the pages, build the tools, test the outputs and answer the error reports myself. There is no content team and no contributed content behind me — if a page carries my name, I am the person who checked it.

My checking process has three steps, and it is the same for a conversion factor as for a calorie value. First, the figure is taken from the primary published source — for this site that means sources such as World Aquatics, USA Swimming, the Compendium of Physical Activities and IRONMAN's athlete guides — never copied from another calculator site. Second, the worked examples on each page are run through the site's own code, and that code is covered by automated tests built around the published examples, so a broken formula fails loudly instead of shipping quietly. Third, the page states its own limits: where a number is an estimate, where a published range is a coaching convention rather than an official standard, and where real-world variation will move the answer. The Methodology page lists this site's sources in full, and the editorial policy sets out the standards every page is held to, including how corrections are made and dated.

• Swim Pace Calculator — the homepage tool: pace per 100, splits and send-offs from a single swim time.
• Methodology — every formula and published source behind the tools.
• Editorial Policy — how pages are researched, verified and corrected.
• About — why this site exists and how it is built.

One honest limit, stated plainly: I am a developer, not a swim coach, and not a medical professional. Nothing on this site is coaching, and nothing on it is medical advice. The calculators give training estimates worked out from published formulas — useful for planning sessions and races, but your coach, your doctor and the pace clock all outrank a website. If you spot an error anyway, I want to hear about it: the report-an-error page reaches me directly, and I read every report myself.