Legal

Accessibility Statement

We want everyone to be able to use this site, whatever device or assistive technology they use. This page describes what we have done and where we know we fall short.

Our aim

We aim for the site to meet the Web Content Accessibility Guidelines (WCAG) 2.2 at level AA. That is the standard we design and test against.

What we have done

Structure. Every page has a single main heading and headings in a logical order. Navigation, main content and footer are marked as landmarks, and a “Skip to content” link is the first thing a keyboard user reaches.

Keyboard. Everything on the site, including the calculators, the menu and the contact form, can be used with a keyboard alone. Focus is always visible, with a high-contrast outline.

Calculators. Every input has a visible label. Hints and error messages are linked to their fields so that screen readers announce them. Errors are described in words, not by color alone, and focus moves to the first field that needs attention. Results are announced when they change, and each result includes a text breakdown and a table, so nothing depends on the diagram.

Text and color. Body text is at least 17 pixels and can be enlarged to 200% without loss of content. Text meets a contrast ratio of at least 4.5 to 1 against its background. Color is never the only way information is conveyed.

Touch. Buttons and inputs are at least 44 pixels high, and the layout adapts to narrow screens without horizontal scrolling of the page.

Images and diagrams. Diagrams have text descriptions, and the information in them is also given in the surrounding text or tables. Decorative images are hidden from screen readers.

Motion. The site has no auto-playing video, animation or carousels. Smooth scrolling is turned off for visitors who have asked their device to reduce motion.

No scripts required for reading. All text, tables, formulas and worked examples are in the page itself and can be read without JavaScript. Each calculator page also shows an example result worked out in advance. JavaScript is needed only to calculate with your own numbers.

Print. Calculator shopping lists and the measurement worksheet have print layouts with large, plain text.

Known limitations

  • Wide tables on small screens. Some reference tables are wider than a phone screen and scroll sideways within their own area. They remain readable with screen readers, but sideways scrolling is less convenient.
  • Calculator diagrams. The diagrams that update with your measurements are described by a short label, not a full description of every dimension. The same dimensions appear in the breakdown table beside them.
  • Advertisements. Ads are provided by third parties, and we cannot guarantee that every ad meets the same standard as our own content. Ads are labeled and kept out of the reading order of the calculators.
  • Mathematical notation. Formulas are written in plain text with symbols such as × and ÷. Some screen readers do not announce these symbols by default. Each formula is also explained in a sentence.

We are working on the first two, and we would like to hear which of these matter most to you.

How we test

Pages are checked with keyboard-only navigation, at 200% and 400% zoom, at phone width, and with automated accessibility checks for contrast, labels and structure. Automated checks do not catch everything, which is why reports from people who use assistive technology every day are so valuable.

Tell us about a problem

If you cannot use part of the site, or something is harder than it should be, please tell us.

It helps to know the page, what you were trying to do, and the browser and any assistive technology you were using. We aim to reply within a week and to fix confirmed problems promptly. If a calculator is not usable for you, tell us what you were trying to work out and we will do our best to help.

This statement

This statement was prepared on October 4, 2026, from our own review of the site. It is reviewed whenever the site’s design or features change.