About

About this calculator

One person, one tape measure's worth of patience, and a strong opinion: a size chart should show where its numbers came from.

Ian Welkins

Independent web developer · Houston, Texas

I'm Ian Welkins, an independent web developer based in Houston, Texas. I build small, single-purpose calculator websites: one tool, one job, its working shown. No sign-up, no accounts, nothing to install.

This site exists because dress sizing is genuinely broken. There is no enforced standard for what a size 10 is, brands publish charts that disagree with each other by up to two inches at the same label, and shoppers are left holding three measurements and a prayer. So I gathered the published charts — the standards documents and the major retailers' own tables — cross-checked them line by line, and built calculators that run on the consensus, say so openly, and show which of your measurements decided your result.

This site is researched, built and maintained by me personally. I read the charts, encode them into the calculators, test the outputs, and answer the error reports. Where a page names a source — ASTM, ISO, a published brand chart — that is the document the figures were taken from, checked on the date the page shows.

You can find me, and check that for yourself, on these profiles:

GitHub — my projects and code
Dev.to — notes on building these tools
About.me — all my sites and profiles in one place
Gravatar — my verified profile

Found a figure that disagrees with a current chart? Tell me through the report-error page — I read every report myself. For anything else, the contact page is the way to reach me.

How the site is built

How these tools are made

Charts first, code second

Every calculator starts as a spreadsheet of published measurements. The chart is settled and sourced before a line of code is written, and the code is then tested against hand-worked examples — the same worked examples you can see on each page.

Working shown, always

Each tool names the measurement that governed your result, states its assumptions, and prints its limits. A calculator that can't explain itself shouldn't be sizing anybody.

Corrections are public work

When a reader reports an error and is right, the fix goes into the chart data, the page's examples are re-checked, and the "last verified" date moves. The editorial policy sets out the whole process.

A note on AI

Honestly, about the tools behind the tools

I use AI as a drafting and coding assistant when building these sites — for first drafts of text and for scaffolding code. Every chart value, every worked example and every claim that reaches a page is checked by me against the published sources named on the page before it ships, and the calculators' outputs are tested against hand calculations. If something on this site is wrong, it's my error, not a machine's excuse — and the report-error page is how it gets fixed.

Every dress tool