Free Size Charts for Your Online Store

Fit is the single biggest reason clothing comes back. Two free tools fix the two halves of it: a size chart built from your own measurements, and a working size calculator for the conversions every shopper gets wrong. No signup, no monthly app fee, and nothing your customers type is ever collected.

Start with a chart of your own sizes

No general tool knows how your garments run. You do. The size chart builder turns that knowledge into a chart a shopper can actually use: type or paste your sizes and measurements, and take away a finished chart.

It does three things the usual chart makers and a spreadsheet screenshot do not:

• It checks your numbers. A medium narrower than the small, a chest smaller than the waist, a gap where a 37 inch chest has no row, one centimeter figure typed into an inch column. Each of those is a return waiting to happen, and the builder points at the exact cell and says why in plain words. It never blocks you. It explains.
• It says which kind of chart it is. Body measurements and garment measurements differ by several inches on the same item, and a shopper who reads one as the other orders the wrong size from a perfectly correct chart. The builder asks which you are publishing and labels the result, with the right instruction for each.
• It answers the shopper, not just shows a table. The hosted version includes a find your size box. A shopper types one measurement and their row lights up, or they are told they sit between M and L and what to do about it for that kind of garment. Their number never leaves their browser.

You can take the chart away three ways: a hosted chart you paste in as one snippet, plain HTML you can restyle, or a PNG image for marketplaces that strip HTML. The whole chart lives inside its own link, so there is no account and nothing is stored on our side.

Build your size chart

Why this is worth ten minutes

You already know the number that hurts: somewhere around a quarter of online apparel orders come back, and fit is the reason customers give more than any other. One 2025 consumer survey found 61 percent of shoppers had returned clothing simply because it did not fit (figures collected in Shopify's guide to sizing charts). Sizing is also the reason people give for choosing a physical store over your website: in a shop they can try it on, and on your product page they are guessing.

A size chart image helps. A chart that has been checked and says what it measures helps more. The hosted version goes further and finds the shopper's row. A calculator beside it helps again, because it does the conversion arithmetic your customer would otherwise get wrong. Together they answer the question shoppers actually have. That question is "what size am I in your sizes," not "what does 40 mean."

Then add a calculator for the part that is universal

Your chart covers how your garments run. Some questions are the same in every store: what a US 9 is in EU sizes, how to measure a neck, how a knuckle measurement becomes a glove size. Every calculator on Sizeaholic can be embedded on your store for those, free, on any plan, on any platform that lets you paste HTML. The embed runs the same code as the page on our site: same formulas, same cited sources, same measuring guidance. When we improve a calculator, your embed updates automatically. There is nothing to install and nothing to maintain.

<iframe id="sizeaholic-shoe-size-converter" src="https://sizeaholic.com/embed/shoe-size-converter/" style="width:100%;max-width:520px;height:900px;border:1px solid #e3e8f0;border-radius:12px;" title="Shoe Size Converter" loading="lazy"></iframe>
<p style="font-size:13px;">Calculator by <a href="https://sizeaholic.com/shoe-size-converter/" rel="nofollow">Sizeaholic</a></p>
<script>window.addEventListener("message",function(e){if(e.origin!=="https://sizeaholic.com"||!e.data||e.data.sizeaholic!=="height")return;var f=document.getElementById("sizeaholic-shoe-size-converter");if(f&&e.source===f.contentWindow)f.style.height=e.data.value+"px";});</script>

Copy code

Swap shoe-size-converter for whichever calculator fits the product. The full list of slugs is on our embedding page, and every calculator page has a </> Add to your website button that hands you that calculator's finished snippet.

Which calculator for which store

Adding either one to your platform

The hosted chart from the builder and the calculator embed are both a short snippet of HTML, so they go in the same way.

Shopify

Go to Online Store, then Themes, then Customize. Open the product template, add a block or section of type Custom Liquid where you want the chart to appear, and paste the snippet in. Save, and it shows on every product using that template. If you would rather have it on one page only, create a page and paste the snippet using the </> HTML view in the rich text editor.

WooCommerce

Edit the product, and in the description add a Custom HTML block with the snippet. For every product at once, add it to a shared block or your product template in the site editor.

Anything else

Squarespace (Code block), Wix (Embed HTML), BigCommerce, Magento, WordPress, or plain HTML: paste the snippet anywhere page HTML is accepted. The iframe is self-contained. For a marketplace listing that accepts no HTML at all, use the PNG from the builder as one of your product images.

You do not need to tune the height. The last line of each snippet is a small listener: the frame is told how tall it needs to be and resizes itself, including the moment a shopper gets their size and the result makes it taller. The height written in the snippet is just the starting value.

If your theme strips script tags, paste the rest anyway. The frame keeps its starting height and scrolls internally if it has to, so you lose the automatic fit and nothing else.

What each tool does, and what it does not

Worth being straight with you, because it decides where they help. Our calculators convert between sizing systems and turn body measurements into standard sizes. They do not know your patterns. If your jeans run a half size small, no general calculator can know that, and any tool that claims otherwise is guessing with confidence.

That is the gap the builder fills, and it has limits of its own. It checks that your numbers are consistent with each other. It cannot check that they are true, because only a tape measure on your actual garment can do that. Measure a real sample of each size rather than copying a supplier's sheet, and the chart is as good as a chart gets.

So the honest way to use these is as a pair. The calculator handles what is genuinely universal. Your chart handles what only you know. Add one line of your own beside them, something like "our slim fit runs one size small, consider sizing up," and the three together answer the customer's real question.

The difference between body measurements and garment measurements runs through all of this. We wrote it up for shoppers at body vs garment measurements, including an ease calculator. It is worth five minutes before you decide which kind of chart to publish.

Privacy, stated plainly

Both tools do their work in the visitor's browser. A shopper's measurements are never transmitted, never stored, and never reach us or you. There is no account and no database. Your own chart is not stored either: every size and number in it is carried inside the chart's link.

One thing you should know for your own privacy page. The frame loads Google Analytics, the same as the pages on our site, and Google Analytics sets cookies. It tells us which calculator or chart was used and which site it was shown on. It never receives a measurement, because measurements never leave the browser. If your store asks visitors for cookie consent, treat the embed as you would any other embedded content that uses Google Analytics. Our privacy policy has the details, and the page around the embed remains governed by your own policy.

The license, in plain words

Both are free for any store, commercial or not, with no traffic limit and no revenue share. For a calculator embed, keep the attribution link under it, use the snippet as provided, and do not present the calculator as your own work. For a chart from the builder, the numbers are yours: the HTML and PNG versions can drop our credit line entirely, and the hosted version keeps one small credit inside the frame. The full wording is in our Terms of Use. That is the entire deal, and there is no upsell behind it.

Need one we have not built?

If you sell something whose sizing deserves an honest calculator and we do not have it yet, or the builder is missing something your charts need, tell us. Several of our tools exist because somebody asked. We build them, you use them, and they stay free.

Frequently asked questions

Last updated 17 September 2026